Antibodies specific for vascular endothelial growth factor-B

ABSTRACT

VEGF-B polypeptides from the PDGF family of growth factors having the property of promoting mitosis and proliferation of vascular endothelial cells, DNA sequences encoding these polypeptides, pharmaceutical compositions containing them and antibodies which react with them. The VEGF-B polypeptides are useful in stimulating angiogenesis as well as in diagnostic applications.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 08/609,443, filedMar. 1, 1996, now U.S. Pat. No. 5,840,693, which in turn is acontinuation-in-part of application Ser. No. 08/569,063, filed Dec. 6,1995, now U.S. Pat. No. 5,928,939, which in turn is acontinuation-in-part of application Ser. No. 08/469,427, filed Jun. 6,1995, now U.S. Pat. No. 5,607,918, which in turn is acontinuation-in-part of application Ser. No. 08/397,651, filed Mar. 1,1995, now abandoned.

BACKGROUND OF THE INVENTION

Angiogenesis, or the proliferation of new capillaries from pre-existingblood vessels, is a fundamental process necessary for normal growth anddevelopment of tissues. It is a prerequisite for the development anddifferentiation of the vascular tree, as well as for a wide variety offundamental physiological processes including embryogenesis, somaticgrowth, tissue and organ repair and regeneration, cyclical growth of thecorpus luteum and endometrium, and development and differentiation ofthe nervous system. In the female reproductive system, angiogenesisoccurs in the follicle during its development, in the corpus luteumfollowing ovulation and in the placenta to establish and maintainpregnancy. Angiogenesis additionally occurs as part of the body's repairprocesses, e.g. in the healing of wounds and fractures. Angiogenesis isalso a factor in tumor growth, since a tumor must continuously stimulategrowth of new capillary blood vessels in order to grow.

Capillary blood vessels consist of endothelial cells and pericytes.These two cell types carry all of the genetic information to form tubes,branches and entire capillary networks. Specific angiogenic moleculescan initiate this process. In view of the physiological importance ofangiogenesis, much effort has been devoted to the isolation,characterization and purification of factors that can stimulateangiogenesis. A number of polypeptides which stimulate angiogenesis havebeen purified and characterized as to their molecular, biochemical andbiological properties. For reviews of such angiogenesis regulators, seeKlagsbrun et al., “Regulators of Angiogenesis”, Ann. Rev. Physiol.,53:217-39 (1991); and Folkman et al., “Angiogenesis,” J. Biol. Chem.,267:10931-934 (1992). Recent results have implicated several endothelialreceptor tyrosine kinases (RTKs) in the establishment and maintenance ofthe vascular system.

One such growth factor, which is highly specific as a mitogen forvascular endothelial cells, is termed vascular endothelial growth factor(VEGF). See Ferrara et al., “The Vascular Endothelial Growth FactorFamily of Polypeptides,” J. Cellular Biochem., 47:211-218 (1991);Connolly, “Vascular Permeability Factor: A Unique Regulator of BloodVessel Function,” J. Cellular Biochem., 47:219-223 (1991). VEGF is apotent vasoactive protein that has been detected in media conditioned bya number of cell lines including bovine pituitary follicular cells. VEGFis a glycosylated cationic 46-48 kD dimer made up of two 24 kD subunits.It is inactivated by sulfhydryl reducing agents, resistant to acidic pHand to heating, and binds to immobilized heparin. VEGF is sometimesreferred to as vascular permeability factor (VPF) because it increasesfluid leakage from blood vessels following intradermal injection. Italso has been called by the name vasculotropin.

Four different molecular species of VEGF have been detected. The 165amino acid species has a molecular weight of approximately 46 kD and isthe predominant molecular form found in normal cells and tissues. A lessabundant, shorter form with a deletion of 44 amino acids betweenpositions 116 and 159 (VEGF₁₂₁), a longer form with an insertion of 24highly basic residues in position 116 (VEGF₁₈₉), and another longer formwith an insertion of 41 amino acids (VEGF₂₀₆), which includes the 24amino acid insertion found in VEGF₁₈₉, are also known. VEGF₁₂₁ andVEGF₁₆₅ are soluble proteins. VEGF₁₈₉ and VEGF₂₀₆ appear to be mostlycell-associated. All of the isoforms of VEGF are biologically active.For example, each of the species when applied intradermally is able toinduce extravasation of Evans blue.

The various species of VEGF are encoded by the same gene and arise fromalternative splicing of messenger RNA. This conclusion is supported bySouthern blot analysis of human genomic DNA, which shows that therestriction pattern is identical using either a probe for VEGF₁₆₅ or onewhich contains the insertion in VEGF₂₀₆. Analysis of genomic clones inthe area of putative mRNA splicing also shows an intron/exon structureconsistent with alternative splicing.

The different isoforms of VEGF have different chemical properties whichmay regulate cellular release, compartmentalization, bioavailability andpossibly also modulate the signalling properties of the growth factors.

Analysis of the nucleotide sequence of the VEGF gene indicates that VEGFis a member of the platelet-derived growth factor (PDGF) family. VEGFand PLGF are ligands for two endothelial RTKs, flt-1 (VEGF receptor 1,VEGFR1) and flk-1/KDR (VEGF receptor 2, VEGFR2). The amino acid sequenceof VEGF exhibits approximately 20% homology to the sequences of the Aand B chains of PDGF, as well as complete conservation of the eightcysteine residues found in both mature PDGF chains. VEGF₁₆₅, VEGF₁₈₉ andVEGF₂₀₆ also contain eight additional cysteine residues within thecarboxy-terminal region. The amino-terminal sequence of VEGF is precededby 26 amino acids corresponding to a typical signal sequence. The matureprotein is generated directly following signal sequence cleavage withoutany intervening prosequence. The existence of a potential glycosylationsite at Asn⁷⁴ is consistent with other evidence that VEGF is aglycoprotein, but the polypeptide has been reported to exist in bothglycosylated and deglycosylated species.

Like other cytokines, VEGF can have diverse effects that depend on thespecific biological context in which it is found. VEGF and its highaffinity receptors flt-1 and KDR/flk-1 are required for the formationand maintenance of the vascular system as well as for both physiologicaland pathological angiogenesis. VEGF is a potent endothelial cell mitogenand directly contributes to induction of angiogenesis in vivo bypromoting endothelial cell growth during normal embryonic development,wound healing, and tissue regeneration and reorganization. VEGF is alsoinvolved in pathological processes such as growth and metastasis ofsolid tumors and ischemia-induced retinal disorders. A most strikingproperty of VEGF is its specificity. It is mitogenic in vitro at 1 ng/mlfor capillary and human umbilical vein endothelial cells, but not foradrenal cortex cells, corneal or lens epithelial cells, vascular smoothmuscle cells, corneal endothelial cells, granulosa cells, keratinocytes,BHK-21 fibroblasts, 3T3 cells, rat embryo fibroblasts, human placentalfibroblasts and human sarcoma cells. The target cell specificity of VEGFis thus restricted to vascular endothelial cells. VEGF can trigger theentire sequence of events leading to angiogenesis and stimulatesangiogenesis in vivo in the cornea and in a healing bone graft model. Itis able to stimulate the proliferation of endothelial cells isolatedfrom both small and large vessels. Expression of VEGF mRNA is temporallyand spatially related to the physiological proliferation of capillaryblood vessels in the ovarian corpus luteum or in the developing brain.VEGF expression is triggered by hypoxia so that endothelial cellproliferation and angiogenesis appear to be especially stimulated inischemic areas. VEGF is also a potent chemoattractant for monocytes. Inaddition, VEGF induces plasminogen activator and plasminogen activatorinhibitor in endothelial cells.

Tumor cells release angiogenic molecules such as VEGF, and monoclonalantibodies to VEGF have been shown to inhibit the growth of certaintypes of tumor such as rhabdomyosarcoma. See Kim et al., “Inhibition ofVascular Endothelial Growth Factor-Induced Angiogenesis Suppresses TumorGrowth in vivo,” Nature, 362:841-844 (1993). This suggests that blockingVEGF action is of potential therapeutic significance in treating tumorsin general, and highly-vascularized, aggressive tumors in particular.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a new growth factor havingthe property of promoting proliferation of endothelial cells.

Another object of the invention is to provide isolated DNA sequenceswhich encode a new growth factor which promotes proliferation ofendothelial cells.

It is also an object of the invention to provide new products which maybe useful in diagnostic and/or therapeutic applications.

These and other objects are achieved in accordance with the presentinvention by providing an isolated DNA which codes for a proteinexhibiting the following characteristic amino acid sequence (SEQ IDNO:16):

Pro-Xaa-Cys-Val-Xaa-Xaa-Xaa-Arg-Cys-Xaa-Gly-Cys-Cys

and having the property of promoting proliferation of endothelial cellsor mesodermal cells, the DNA being selected from the group consisting ofthe DNA of FIGS. 1 and 2 (SEQ ID NO:1), the DNA of FIG. 3 (SEQ ID NO:4),the DNA of FIG. 5 (SEQ ID NO:6); the DNA of FIG. 7 (SEQ ID NO:8), theDNA of FIG. 10 (SEQ ID NO:10), the DNA of FIG. 12 (SEQ ID NO:12), theDNA of FIG. 14 (SEQ ID NO:14), and DNA's which hybridize under stringentconditions with at least one of the foregoing DNA sequences.

In accordance with further aspects of the invention, the objects arealso achieved by providing a protein exhibiting the followingcharacteristic amino acid sequence

Pro-Xaa-Cys-Val-Xaa-Xaa-Xaa-Arg-Cys-Xaa-Gly-Cys-Cys (SEQ ID NO:16) andhaving the property of promoting proliferation of endothelial cells ormesodermal cells, which protein comprises a sequence of amino acidssubstantially corresponding to an amino acid sequence selected from thegroup consisting of the amino acid sequence of FIG. 1 (SEQ ID NO:2), theamino acid sequence of FIG. 2 (SEQ ID NO:3), the amino acid sequence ofFIG. 4 (SEQ ID NO:5), the amino acid sequence of FIG. 6 (SEQ ID NO:7),the amino acid sequence of FIG. 8 (SEQ ID NO:9), the amino acid sequencof FIG. 11 (SEQ ID NO:11), the amino acid sequence of FIG. 13 (SEQ IDNO:13), and the amino acid sequence of FIG. 15 (SEQ ID NO:15).

In further aspects of the invention, the objects are achieved byproviding pharmaceutical preparations which comprise such proteins; andby providing antibodies which react with or recognize such proteins.

The novel growth factor of the present invention, referred tohereinafter as vascular endothelial growth factor B or VEGF-B, has closestructural similarities to VEGF and to placenta growth factor (PlGF).All of the VEGF-B forms contain the characteristic amino acid sequence

Pro-Xaa-Cys-Val-Xaa-Xaa-Xaa-Arg-Cys-Xaa-Gly-Cys-Cys (SEQ ID NO:16)(wherein Xaa represents a variable residue), which is an earmark of thePDGF/VEGF family of growth factors. This characteristic amino acidsequence can be found at amino acids 70 to 82 in FIGS. 4, 6, 8, 11, 13and 15.

Clinical applications of the invention include diagnostic applications,acceleration of angiogenesis in wound healing, and inhibition ofangiogenesis. Quantitation of VEGF-B in cancer biopsy specimens may beuseful as an indicator of future metastatic risk. Topical application ofVEGF-B preparations to chronic wounds may accelerate angiogenesis andwound healing. VEGF-B may be used in a manner analogous to VEGF.

According to yet further aspects of the invention, the objects areachieved by providing diagnostic/prognostic means typically in the formof test kits. For example, in one embodiment of the invention there isprovided a diagnostic/prognostic test kit comprising antibodies to thenew growth factor of the invention and means for detecting, and morepreferably evaluating, binding between the antibodies and the new growthfactor of the invention. In one preferred embodiment of thediagnostic/prognostic means according to the invention, either theantibody or the new growth factor is labelled, and either the antibodyor the growth factor is substrate-bound, such that the growthfactor-antibody interaction can be established by determining the amountof label attached to the substrate following binding between theantibody and the growth factor. In a particularly preferred embodimentof the invention, the diagnostic/prognostic means may be provided as aconventional ELISA kit.

In another alternative embodiment, the diagnostic/prognostic means maycomprise PCR means for establishing the genomic sequence structure of aVEGF-B gene of a test individual and comparing this sequence structurewith that disclosed in this application in order to detect anyabnormalities, with a view to establishing whether any aberrations inVEGF-B expression are related to a given disease condition.

A yet further aspect of the invention concerns an antibody whichrecognizes VEGF-B and which is suitably labelled.

Another aspect of the invention concerns the provision of apharmaceutical composition comprising either VEGF-B protein orantibodies thereto. Compositions which comprise VEGF-B protein mayoptionally further comprise either VEGF or heparin or both.

According to an additional aspect of the invention the manufacture of amedicament is provided which comprises VEGF-B protein and heparin fortreating conditions characterized by lack of, or reduction in,angiogenesis.

In another aspect, the invention relates to a protein dimer comprisingVEGF-B protein, particularly a disulfide-linked dimer. The proteindimers of the invention include both homodimers of VEGF-B protein andheterodimers of VEGF-B and VEGF.

According to a yet further aspect of the invention there is provided amethod for facilitating release of VEGF and/or VEGF-B from a cellcomprising exposing a cell which expresses either or both of theaforementioned growth factors to heparin.

Another aspect of the invention involves providing a vector comprisingan anti-sense nucleotide sequence which is complementary to at least apart of the DNA sequences disclosed herein which encode the new growthfactor of the invention which promotes proliferation of endothelialcells. According to a yet further aspect of the invention such a vectorcomprising an anti-sense sequence may be used to inhibit, or at leastmitigate, VEGF-B expression. The use of a vector of this type to inhibitVEGF-B expression is favored in instances where VEGF-B expression isassociated with a disease such as in instances where tumors produceVEGF-B in order to provide for angiogenesis. Transformation of suchtumor cells with a vector containing an anti-sense nucleotide sequencewould suppress or retard angiogenesis and so would inhibit or retardgrowth of the tumor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the nucleotide sequence of the (partial) cDNA clone ofVEGF-B (SEQ ID NO:1) and the amino acid sequence of the protein segment(SEQ ID NO:2) coded by the first reading frame of the cDNA;

FIG. 2 repeats the nucleotide sequence of the (partial) cDNA clone ofVEGF-B (SEQ ID NO:1) and the amino acid sequence of the protein segment(SEQ ID NO:3) coded by the second reading frame of the cDNA;

FIG. 3 shows the nucleotide sequence of the coding region of a fulllength cDNA clone of murine VEGF-B₁₆₇ (SEQ ID NO:4);

FIG. 4 shows the amino acid sequence of murine VEGF-B₁₆₇ (SEQ ID NO:5);

FIG. 5 shows the nucleotide sequence of the coding region of a cDNAclone of VEGF-B₁₇₄ (SEQ ID NO:6);

FIG. 6 shows the amino acid sequence of VEGF-B₁₇₄ (SEQ ID NO:7);

FIG. 7 shows the nucleotide sequence of a cDNA clone of VEGF-B₁₁₂ (SEQID NO:8);

FIG. 8 shows the amino acid sequence of VEGF-B₁₁₂ (SEQ ID NO:9);

FIG. 9 shows a comparison of the amino acid sequences of mVEGF-B₁₆₇,mVEGF₁₆₄, hPlGF, mPDGF A, and mPDGF B;

FIG. 10 shows the nucleotide sequence of a clone of human VEGF-B₁₆₇ (SEQID NO:10);

FIG. 11 shows the amino acid sequence of human VEGF-B₁₆₇ (SEQ ID NO:11);and

FIG. 12 shows the nucleotide sequence of murine VEGF-B₁₈₆ (SEQ IDNO:12);

FIG. 13 shows the amino acid sequence of murine VEGF-B₁₈₆ (SEQ IDNO:13);

FIG. 14 shows the nucleotide sequence of human VEGF-B₁₈₆ (SEQ ID NO:14);

FIG. 15 shows the amino acid sequence of human VEGF-B₁₈₆ (SEQ ID NO:15);

FIG. 16 shows an amino acid sequence comparison of murine and humanVEGF-B₁₆₇ and VEGF-B₁₈₆ isoforms (SEQ ID NOS: 5, 11, 13 & 15).

FIG. 17 shows the schematic structure of mouse and human genes forVEGF-B;

FIG. 18 shows a hydrophilicity analysis of murine VEGF-B₁₆₇ andVEGF-B₁₈₆ isoforms;

FIG. 19 shows a phylogenetic analysis of the VEGF/PDGF family of growthfactors;

FIG. 20 is a graph showing the induction of [³H]thymidine incorporationby VEGF-B, VEGF and bFGF for human umbilical vein endothelial cells(HUVEC) and bovine capillary endothelial (BCE) cells;

FIG. 21 is a Northern blot analysis of the expression of VEGF-B₁₈₆transcripts in several mouse and human tissues;

FIG. 22 shows the results of immunoprecipitation and SDS-PAGE analysisof cell culture media and detergent solubilized cell lysates from Cos-1cells transiently transfected with a murine VEGF-B cDNA;

FIG. 23A shows the results of immunoprecipitation and SDS-PAGE analysisof cell culture media from transfected Cos-1 cells separately expressingmurine VEGF-B₁₈₆ and human VEGF₁₆₅;

FIG. 23B shows the results of immunoprecipitation and SDS-PAGE analysisof cell culture media (M) and detergent solubilized cell lysates (L) ofCos-1 cells which coexpress murine VEGF-B₁₈₆ and human VEGF₁₆₅;

FIG. 23C shows the results of immunoprecipitation and SDS-PAGE analysisof cell culture media from Cos-1 cells expressing murine VEGF-B₁₈₆ andhuman VEGF, either separately or in combination, and from mocktransfected control cells;

FIG. 24 is a schematic illustration of the derivation of VEGF-Bpromoter-reporter clones; and

FIG. 25 shows the nucleotide sequence of a 1.55 kb human VEGF-B promoterfragment (SEQ ID NO:17).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention thus is directed to new vascular endothelialgrowth factors, hereinafter referred to as VEGF-B growth factors, whichshare the angiogenic and other properties of VEGF, but which aredistributed and expressed in tissues differently from VEGF.

VEGF-B growth factors are members of the family of platelet derivedgrowth factors and are a growth factors which promote mitosis andproliferation of vascular endothelial cells and/or mesodermal cells.They are produced by expression of DNA sequences which correspond to, orwhich are hybridizable under stringent conditions with, any one of theDNA sequences depicted in FIGS. 1 and 2 (SEQ ID NO:1), FIG. 3 (SEQ IDNO:4), FIG. 5 (SEQ ID NO:6), FIG. 7 (SEQ ID NO:8), FIG. 10 (SEQ IDNO:10), FIG. 12 (SEQ ID NO:12) or FIG. 14 (SEQ ID NO:14). It is intendedto include within the scope of the invention all angiogenic proteinsencoded by DNA sequences which hybridize under stringent conditions toany one of the foregoing DNA sequences. Suitable hybridizationconditions include, for example, 50% formamide, 5×SSPE buffer,5×Denhardts solution, 0.5% SDS and 100 μg/ml of salmon sperm DNA at 42°C. overnight, followed by washing 2×30 minutes in 2×SSC at 55° C.

The invention is also directed to an isolated and/or purified DNA whichcorresponds to, or which hybridizes under stringent conditions with, anyone of the foregoing DNA sequences.

In a further aspect, the invention is directed to antibodies of VEGF-Bgrowth factors, and particularly to monoclonal antibodies.

VEGF-B proteins are believed to interact with protein tyrosine kinasegrowth factor receptors. Details of such receptors are known in the art[See e.g. Wilks, A. F., “Protein Tyrosine Kinase Growth Factor Receptorsand Their Ligands in Development, Differentiation, and Cancer,” Adv.Cancer Res., 60:43-73 (1993)].

Various adult mouse tissues were tested for expression of transcriptscorresponding to VEGF-B by Northern blotting. The size of the mRNA was1.3-1.4 kb. A mouse multiple tissue Northern blot (MTN, Clontech) wasprobed with the ≈0.9 kb SalI/NotI fragment derived from the pPC67 yeastexpression vectors described above. The probe was labelled with ³²P-dCTPusing random priming (specific activity 10⁸⁻¹⁰ ⁹ cpm/μg of DNA). Theblot was hybridized overnight at 42° C. using 50% formamide, 5×SSPEbuffer, 2% SDS, 10×Denhardts solution, 100 μg/ml salmon sperm DNA and1×10⁶ cpm of the labelled probe/ml. The blot was washed at roomtemperature for 2×30 min in 2×SSC containing 0.05% SDS and then for 2×20min at 52° C. in 0.1×SSC containing 0.1% SDS. The blot was then exposedat −70° C. for three days using intensifying screens. Kodak XAR film wasused. The relative expression levels as determined by visualexaminations of the film are listed in the following table:

TABLE 1 Distribution of VEGF-B Transcripts in the Adult Mouse TissueRelative Expression Level Heart +++++ Brain +++ Spleen (+) Lung ++Liver + Skeletal Muscle ++++ Kidney +++ Testis (+) +++++ = very strongexpression; ++++ = strong expression; +++ = moderate expression; ++ =rather weak expression; + = weak expression; (+) = very weak expression.

A human multiple tissue Northern blot (MNT) from Clontech was probedusing the murine partial cDNA to determine relative VEGF-B expressionlevels in various human tissues. The size of the transcript was 1.3-1.4kb. The conditions were identical to those used for the mouse Northernblot described above. The relative VEGF-B transcript levels for thehuman Northern blot are listed in the following Table 2. For comparisonpurposes, Table 2 also lists relative expression level data from theliterature for VEGF in various mammalian systems.

TABLE 2 Relative Expression Levels VEGF-B VEGF (Northern (fromliterature) blot) guinea Tissues human human murine pig heart +++++ +++++ +++ brain + + + placenta + lung + ++++ ++ liver (+) ++ (+) +skeletal ++++ +++ + muscle kidney + ++ + ++ pancreas +++ spleen ++ − +thymus + − prostate +++ testis ++ (+) ovary +++ − small ++ intestinecolon +++ peripheral + blood leucocytes

From a comparison of Table 1 and Table 2 it can be seen that mouse andhuman tissue expression levels of VEGF-B transcripts are relativelysimilar with the highest expression levels being found in heart andskeletal muscle. Significant differences may be seen in brain and kidneytissue. It should also be noted that tissues containing a largeproportion of both muscular and epithelial cells, such as prostate,pancreas and colon from which some of the most common human tumorsoriginate, express relatively high levels of VEGF-B.

A comparison of the relative expression levels of VEGF and VEGF-B inhuman tissues shows some striking differences. VEGF is expressed ratherweakly by human heart tissue, but VEGF-B is very strongly expressed bythe same tissue. On the other hand, VEGF is strongly expressed by humanlung tissue, but VEGF-B is only weakly expressed by human lung tissue.In a similar vein, human liver tissue expresses VEGF at a moderatelevel, but VEGF-B is expressed only very weakly. These data evidencethat despite their general similarities, the actions of VEGF and VEGF-Bare not completely identical.

The expression of VEGF-B transcripts was further analyzed in mouse andhuman tissues by Northern blotting and compared with the expression ofVEGF transcripts. Mouse and human multiple tissue Northern (MTN) blots(Clontech) were hybridized with a ³²P-labelled mouse VEGF-B probe (≈0.9kb SalI/NotI insert of the clone pcif 2). VEGF expression was analyzedwith ³²P-labelled VEGF₁₆₅ cDNA as the probe. The hybridizations werecarried out at 42° C. in 50% deionized formamide, 5×SSC pH 7.0, 1% SDS,5×Denhardt's solution and 100 μg/ml of denatured salmon sperm DNA. Thefilters were washed 2×30 min at 52° C. in 2×SSC containing 0.5% SDS andexposed to Kodak XAR film for 2-5 days at −70° C. using intensifyingscreens. In situ hybridization analysis of adult mouse tissues from CBAmice and of embryos derived from matings of CBA and NMRI mice werecarried out essentially as previously described by Korhonen et al.,Blood, 80, 2548-55 (1992). The RNA probes (a 383 bp antisense probe anda 169 bp sense probe) were generated from a linearized plasmidcontaining a 440 bp Sal I/Sac I fragment derived from the pcif 2 cDNAclone. Radiolabelled RNA was synthesized using T7 and SP6 RNApolymerases and [³⁵S]UTP (Amersham Inc.). Alkaline hydrolysis of theprobes was omitted. Hematoxylin was used for counterstaining. Controlhybridizations with sense strand and RNAse A-treated sections did notgive signals above background.

In mouse tissues the most abundant expression of the 1.4 kb VEGF-Btranscript was detected in heart, brain, skeletal muscle, and kidney.The major 3.7 kb VEGF transcript was is expressed in heart, brain, lung,skeletal muscle and kidney. In human tissues, the most abundantexpression of the 1.4 kb VEGF-B transcript and the major 3.7 and 4.5 kbVEGF transcripts were detected in heart, skeletal muscle, pancreas andprostate. Thus, although clear quantitative differences exist, itappears that VEGF-B and VEGF are coexpressed in many human and mousetissues.

The expression of VEGF-B transcripts was further examined by in situhybridization in sections from adult mouse heart and skeletal muscle andfrom the early (E 10) mouse embryo. In the adult heart, VEGF-Btranscripts are prominently expressed in the myocardium, while nospecific signal is detected in arterial smooth muscle. In adult striatedmuscle, VEGF-B transcripts are expressed by some of the myofiberswhereas others seem to lack the transcript. In the E 10 mouse embryo,VEGF-B transcripts are detected mainly in the developing heart. Themyocardium of the adult mouse heart has a prominent signal. In striatedmuscle, VEGF-B expression is seen in subpopulations of myofibers. Strongsignals were also obtained in the developing heart of the E10 mouseembryo. Other embryonic structures expressed lower or undetectablelevels of transcripts for VEGF-B. Taken together, these tests indicatethat VEGF-B transcrips are expressed primarily in muscular tissues.VEGF-B is particularly abundant in heart and skeletal muscle and isco-expressed with VEGF in these and other tissues. In transfected cells,VEGF-B forms cell surface associated, disulfide-linked homodimers andheterodimers with VEGF when coexpressed. A Northern blot analysis of theexpression of VEGF-B₁₈₆ transcripts in several mouse and human tissuesusing a VEGF-B₁₈₆ isoform specific probe is shown in FIG. 21.

The chromosomal location of the VEGF-B gene was assessed by Southernblotting and polymerase chain reaction analysis of somatic cell hybridsand fluorescense in situ hybridization (FISH) of metaphase chromosomes.The VEGF-B gene was found on chromosome 11q13, proximal of the cyclin D1gene. It is interesting that although the cyclin D1 gene is amplified ina number of human carcinomas, the VEGF-B gene was not amplified inseveral mammary carcinoma cell lines which contained amplified cyclinD1. Nevertheless, mutations in the VEGF-B gene may be related tovascular malformations and/or cardiovascular diseases.

Unless otherwise indicated, the following Examples used standardmolecular biology techniques and procedures as disclosed in Ausubel etal. (eds.), Current Protocols in Molecular Biology, John Wiley & Sons,New York (1992).

EXAMPLE 1

Partial cDNA Clone with Two Reading Frames

A partial cDNA clone encoding murine VEGF-B was identified as follows. AcDNA library (E 14.5) derived from poly A+ mRNA isolated from 14.5 dayold mouse embryos [Chevray P. and Nathans D., “Protein interactioncloning in yeast: Identification of mammalian proteins that react withthe leucine zipper of Jun,” Proc. Natl. Acad. Sci. USA, 89:5789-93(1992)] was screened for cellular proteins which potentially mightinteract with cellular retinoic acid-binding protein type 1 (CRABP-I)using a yeast two-hybrid interaction trap screening technique asdescribed by Gyuris J., Golemis E., Chertkov H. and Brent R., “Cdil, aHuman G1 and S Phase Protein Phosphatase That Associates with Cdk2,”Cell, 75:791-803 (1993). This screening technique involves a fusionprotein that contains a binding domain and that is known to betranscriptionally inert (the “bait”); reporter genes that have no basaltranscription and that are bound by the bait; and an expression librarywhich encodes proteins expressed as chimeras and whose amino terminicontain an activation domain and other useful moieties (the “prey”). Thescreened library was a 14.5 day mouse embryo plasmid library in theyeast expression vector pPC67 obtained from Dr. Pierre Chevray of theJohns Hopkins University, School of Medicine, 725 North Wolfe St.,Baltimore, Md. 21205. A positive cDNA clone (pcif-2) was recovered fromthe screening. The positive clone was sequenced using well known,conventional techniques and found to encode a protein highly homologousto VEGF and the other members of the PDGF family of growth factors. The≈0.9 kb SalI/NotI insert in the plasmid pPC67 was cloned intopBluescript and fully sequenced using T7 and T3 vector primers togetherwith internal primers. The plasmid pBluescript is commercially availablefrom Stratagene Inc., LaJolla, Calif. The cDNA insert was found to be886 base pairs long and to encode two polypeptides in different readingframes which were homologous to the N-terminal end and the C-terminalend, respectively, of VEGF. This novel growth factor is referred tohereinafter as VEGF-B. The clone is partial and lacks several aminoacids in the amino terminal region and the entire signal sequence.

FIG. 1 shows the nucleotide sequence (SEQ ID NO:1) of this partial cDNAclone of VEGF-B and the amino acid sequence (SEQ ID NO:2) encoded in thefirst reading frame thereof. The DNA sequence of FIG. 1 was obtained byconventional sequencing of a clone (pcif-2) in the yeast expressionvector pPC67. The clone comprised 886 base pairs and encoded a part ofmurine VEGF-B.

The isolated cDNA sequence will hybridize with the mammalian genomicDNA, e.g. either murine or human, which contains the VEGF-B gene. Inaddition to the coding sequence, the genomic DNA will contain one ormore promoter sequence(s) which give and direct expression of VEGF-B inone or more specific tissues. Thus the coding sequence of VEGF-B may belinked to muscle-specific promoter elements which in turn are specificto certain types of muscle fibers.

The nucleotide sequence is translated in two different reading framesinto two different amino acid sequences. There is a stop codon (TGA)within the coding sequence at base pairs 309-311. Thus, VEGF-B comes inseveral splicing variants. The 5′ end of the cloned cDNA sequenceencodes an 102 amino acid long protein with significant homology to theN-terminal domains of VEGF, PlGF and PDGF A and B. In particular, anumber of cysteine residues are perfectly conserved within this group ofproteins. In addition to the nucleotide sequence (SEQ ID NO:1), FIG. 1further depicts the deduced amino acid sequence (SEQ ID NO:2) of thisfirst protein.

Translation of the C-terminal end of the cDNA (base pairs 308-475) in adifferent reading frame results in a protein which is highly homologousto the C-terminal part of VEGF₁₆₅, VEGF₁₈₉ and VEGF₂₀₆. FIG. 2 againshows the nucleotide sequence (SEQ ID NO:1) of FIG. 1, but this timeincludes the deduced amino acid sequece (SEQ ID NO:3) of the secondprotein, which is encoded in the second reading frame and is 54 aminoacids long. It thus appears that the VEGF-B gene encodes differentproteins using alternative splicing of the primary transcript. The lastpart of the clone, encoding the second peptide might be expressed as afunctional protein in other spliced variants of VEGF-B.

The aforedescribed proteins may exist in combined association with anadditional N-terminal sequence of approximately five (5) to ten (10)amino acids, as well as a further leader sequence of approximatelytwenty-one (21) to twenty-eight (28) amino acids. Inasmuch such combinedamino acid sequences exhibit the property of promoting the proliferationof endothelial cells and the DNA sequences which code for such combinedpeptide sequences will hybridize under stringent conditions with the DNAsequence of FIGS. 1 and 2, such amino acid sequences and the DNA whichcodes for them are expressly contemplated to be within the scope of thepresent invention.

EXAMPLE 2

Cloning of Full Length cDNA's for Mouse VEGF-B

Using the approximately 0.9 kb SalI/NotI cDNA insert of the previouslyidentified cDNA clone of Example 1 as a probe, an adult mouse heartlambda ZAP-II cDNA library obtained from Stratagene Inc., of La Jolla,Calif. was screened using standard techniques. The library was titratedand plated as recommended and filters were prepared. Followingprehybridization at 42° C. in 50% formamide, 5×SSPE, 5×Denhartssolution, 1% SDS and 100 ug of salmon sperm DNA/ml, the filters werehybridized at the same temperature and in the same solution containingthe denatured radiolabelled probe using 10⁶ cpm/ml of hybridizationsolution. The probe was labelled using a random priming kit (Amersham).After 16 hours the filters were washed in 2×SSC containing 0.5% SDS for2×30 mins at 52° C. The filters were exposed overnight usingintensifying screens at −70° C. Positive clones were rescreened twotimes until all plaques on a plate were positive. The inserts fromseveral positive clones were subcloned into the plasmid pBluescript SK+by in vivo excision as recommended by the supplier.

Several clones were mapped by restriction enzyme analysis and were foundto fall into two distinct groups characterized by the length of aSpe1/BamH1 restriction fragment. The first of these groups comprisedthree of the restriction mapped clones which each had a 240 bpSpe1/BamH1 restriction fragment. The other group comprised a clone whichhad a 340 bp Spe1/BamH1 fragment. Analysis of this fragment is describedin Example 5.

The three clones which exhibited the 240 bp Spe1/BamH1 restrictionfragment were fully or partially sequenced (Sequenase 2.0, U.S.Biochemicals), and the characteristics of the clones are summarized asfollows:

Nucleotide sequence analyses revealed that two of the cDNA clones weresubstantially identical, although they differed in length, and one had amutation. One of the clones was full length and contained an openreading frame encoding 188 amino acid residues in which the first 21amino acids are a clevable signal sequence. The other of the twosubstantially identical clones terminated at the G of the startinitiation codon. It could be inferred by sequence analysis ofadditional clones that the sequence preceeding the G reads ACCAT. Bothof the clones were found to have the same coding region nucleotidesequence, which is depicted in FIG. 3 (SEQ ID NO:4). The figure omitsthe initial thymine and adenine of the start codon (TAG) which were notpresent in the isolated clones. The deduced amino acid sequence of theopen reading frame of the coding region of both of these two cDNA clonesis shown in FIG. 4 (SEQ ID NO:5). The resulting protein encoded by thissequence is referred to hereinafter as VEGF-B₁₆₇. In each of the proteinnames used herein, the subscript number refers to the number of aminoacids in the mature protein without the signal sequence.

As would be expected, a comparison of the amino acid sequence encoded bythese two clones with the partial amino acid sequence deduced from cDNAclone of Example 1 showed a striking similarity. However, the two openreading frames in the clone of Example 1, each of which encoded an aminoacid sequence homologous to a different portion of VEGF, are bothpresent in the same reading frame in each of these two clones accordingto Example 2. The frame shift in the clone of Example 1 is caused by aninsertion of two extra adenine units which displace the C-terminal partof the clone of Example 1 out of frame. The reason for this is notpresently understood, but may be due to a cloning artifact.

The coding part of the third clone had a nucleotide sequence identicalto those of the preceding two clones except for a 21 bp insertion. FIG.5 shows the nucleotide sequence of this third clone (SEQ ID NO:6). Tofacilitate identification, the 21 extra bases are underlined in theFigure. This insertion gives rise to 7 additional amino acid residues inthe mature protein. Thus the resulting protein encoded by this longercDNA is termed VEGF-B₁₇₄. The amino acid sequence of the protein encodedby the cDNA of FIG. 5 is depicted in FIG. 6 (SEQ ID NO:7). The sevenadditional amino acids also are underlined in the figure for ease ofidentification. The additional amino acids are inserted into thesequence in a splice site, and sequencing of mouse genomic DNA clonesindicates that these additional amino acids are the result of truealternative splicing. Furthermore, based on what is known about thereceptor binding site locations of PDGF, the insertion occurs in aposition in the protein which is probably part of a receptor bindingsite. The insertion is thus likely to affect receptor binding and couldbe of functional importance in influencing antagonist and/or differentreceptor specificify.

EXAMPLE 3

Hybrid cDNA Clone

As previously pointed out this original cDNA clone of Example 1 was notfull length and may contain an artifact. However, if the extreme 5′nucleotide sequence of the clones which encode VEGF-B₁₆₇ and/orVEGF-B₁₇₄ is added, the open reading frame encodes a protein of 133amino acids, yielding a mature protein which is 112 amino acids long andhence is named VEGF-B₁₁₂. The hybrid cDNA sequence encoding VEGF-B₁₁₂(SEQ ID NO:8) is shown in FIG. 7, and the amino acid sequence of thecorresponding protein (SEQ ID NO:9) is illustrated in FIG. 8.

FIG. 9 shows a multiple amino acid sequence alignment for comparisonpurposes of the 167 amino acid variant of mouse Vascular EndothelialGrowth Factor B (mVEGF-B₁₆₇), mouse Vascular Endothelial Growth Factor(mVEGF₁₆₄), human Placenta Growth Factor (hPlGF), mouse Platelet DerivedGrowth Factor A (mPDGF A), and mouse Platelet Derived Growth Factor B(mPDGF B). Amino acid residues identical to mouse VEGF-B₁₆₇ are boxed.The homologous relationship of the sequences is apparent, and the figureclearly demonstrates the conserved structure of the growth factorsbelonging to the PDGF/VEGF family of growth factors, and that VEGF-B isa structural homolog of the other growth factors of this group. Pairwisecomparisons of the amino acid sequences show that mouse VEGF-B isapproximately 43% identical to mouse VEGF₁₆₄, approximately 30%identical to human PlGF, and approximately 20% identical to mouse PDGF Aand B. The conserved cysteine residues are particularly noteworthy. Itcan be seen that the first eight cysteine residues in the N-terminaldomains (i.e. the PDGF-like domains) of the five growth factors areshared by all members of this family, and it is thus evident that theeight cysteine residues, which are involved in intramolecular andintermolecular disulfide bonding, are invariant among these growthfactors. Furthermore, the C-terminal domains of mouse VEGF-B₁₆₇ andVEGF₁₆₄ also display a significant similarity with eight additionalconserved cysteine residues and several stretches of basic amino acids.

EXAMPLE 4

Cloning of Human VEGF-B cDNA

10⁶ λ-clones of human fibrosarcoma cDNA library HT1080 in λgt11(Clontech) were screened with the ≈0.9 kb insert of the mouse VEGF-Bclone pcif 2 according to standard procedures. Among several positiveclones, one, termed H.1 was analyzed more carefully and its nucleotidesequence was determined. The nucleotide sequence indicated that a 207amino acid isoform of human VEGF-B was encoded. Analysis of this isoformis described subsequently in Example 6. Based on the H.1 sequence twooligonucleotides were designed that would amplify the whole codingregion of putative human cDNA corresponding to mouse VEGF-B₁₆₇ isoform:

5′-CACCATGAGCCCTCTGCTCC-3′ (forward) (SEQ ID NO:18)

5′-GCCATGTGTCACCTTCGCAG-3′ (reverse) (SEQ ID NO:19)

These oligonucleotides were used to amplify by polymerase chain reaction(PCR) the whole coding region of human VEGF-B from oligo-dT primed humanerythroleukemia cell (HEL) RNA. The amplified product was cloned intothe pCR II-vector of TA cloning kit (Invitrogen) and sequenced usingstandard techniques. The nucleotide sequence of the human VEGF-B cDNAclone is shown in FIG. 10 (SEQ ID NO:10), and the deduced amino acidsequence of human VEGF-B₁₆₇ is shown in FIG. 11 (SEQ ID NO:11).

The full length mouse cDNA clone of Example 2 and the full length humancDNA clone of Example 4 each encode a polypeptide of 188 amino acidscontaining an N-terminal hydrophobic putative signal sequence. Inanalogy with VEGF, the signal peptidase cleavage site is believed to belocated between Ala 21 and Pro 22. The putative cleavage site of thesignal peptidase is indicated in FIG. 16 by an arrow. Accordingly, theprocessed VEGF-B polypeptides of these two clones each contain 167 aminoacids.

EXAMPLE 5

The clone which exhibited the 340 bp Spe1/BamH1 fragment isolated inExample 2 was analyzed, and the major portion was found to be identicalto the first two clones of Example 2 which exhibited the 240 bpSpe1/BamH1 fragment. The difference is due to the presence of aninsertion in the C-terminal part of the sequence.

This 340 bp Spe1/BamH1 DNA fragement encodes a further isoform of mouseVEGF-B containing 207 amino acids. The coding portion of the DNAencoding this protein (SEQ ID NO:12) is illustrated in FIG. 12, and thetranslated amino acid sequence (SEQ ID NO:13) is illustrated in FIG. 13.After cleavage of the 21 amino acid leader sequence, the mature proteincontains 186 amino acids and is referred to as mVEGF-B₁₈₆. This isoformis clearly a result of alternative DNA splicing as described below withreference to FIG. 17.

EXAMPLE 6

The H.1 clone isolated as described in Example 4 was found to encode a207 amino acid isoform of human VEGF-B. The coding portion of the DNA(SEQ ID NO:14) encoding this protein is illustrated in FIG. 14 and thetranslated amino acid sequence (SEQ ID NO:15) is illustrated in FIG. 15.Again, this isoform, which is designated hVEGF-B₁₈₆, appears to be aproduct of alternative splicing.

Both the mVEGF-B₁₈₆ of Example 5 and the hVEGF-B₁₈₆ of Example 6 includea 101 base pair insertion between nucleotides 414 and 415 of the codingsequence of VEGF-B₁₆₇. Following the insertion, the nucleotide sequencesof these cDNA clones were identical to the correponding VEGF-B₁₆₇sequences. The position of the 101 base pair insertion corresponds tothe exon 5-exon 6 junction in VEGF. The insertion results in aframeshift which causes the C-terminal domains of the two VEGF-Bisoforms to be entirely different.

The divergence of the C-terminal amino acid sequences starting at aminoacid 116 in SEQ ID NOS 11 and 15, which correspond to the two principalVEGF-B isoforms, VEGF-B₁₆₇ and VEGF-B₁₈₆, is reflected by the differentbiochemical characteristics of the two isoforms. The C-terminal domainof VEGF-B₁₆₇ is strongly basic (net charge +13) and binds heparin. TheC-terminal domain of VEGF-B₁₈₆ is weakly basic (net charge +5) and has along stretch of hydrophobic amino acid residues in its C-terminus. Thehydrophobic tail in VEGF-B₁₈₆ is unlikely to behave as a transmembranedomain since this variant of VEGF-B is secreted from cells. Therefore,despite an identical N-terminal domain, these two principal isoforms ofVEGF-B have very different biochemical properties. The absence of thehighly basic heparin-binding domain from VEGF-B₁₈₆ allows the protein tobe freely secreted from cells. However, the secretion of VEGF-B₁₈₆ isremarkably slow; in a pulse chase experiment using transfected cells,VEGF-B₁₈₆ homodimers were not found in the medium before 1 hour. Incontrast, VEGF homodimers and VEGF-B₁₈₆.VEGF dimers appear in the mediumwithin 30 minutes.

FIG. 16 shows the aligned amino acid sequences of mouse and humanVEGF-B₁₆₇ and VEGF-B₁₈₆ (SEQ ID NOS:5, 11, 13 & 15) in one-letter code.Identical residues are enclosed in boxes, while amino acid residueswhich differ between mouse and human VEGF-B₁₆₇ and VEGF-B₁₈₆ isoformsare outside the boxes. Mouse and human VEGF-B display approximately 88%amino acid sequence identity and are highly basic, especially in theirC-terminal regions. The C-terminal domains of murine and human VEGF-B₁₈₆are approximately 85% identical at the amino acid level. The C-terminaldomains of murine and human VEGF-B₁₆₇ are approximately 84% identical atthe amino acid level. Both polypeptides lack the consensus sequence forN-linked glycosylation (N-X-T/S). The arrow indicates the putativecleavage site for the signal peptidase between Ala²¹ and Pro²².Excluding the signal sequences, the mouse and human VEGF-B₁₆₇ amino acidsequences are highly homologous with only 20 replacements out the the167 residues. The replacements are clustered in the N-terminus, in tworegions around amino acids 60 and 145. All cysteine residues in bothVEGF-B₁₆₇ proteins are invariant, but the eight cysteine residues in theC-terminal end of VEGF-B₁₆₇ are not conserved in the VEGF-B₁₈₆ isoforms.It is notable that the mouse and human sequences in the region betweenresidues 66 and 129 are identical apart from one evolutionarilyconserved replacement (Q105R). This is of importance since the receptorbinding domains are found within this portion of the protein (comparedto PDGF structure). From this it can be concluded that it is likely thatmouse and human VEGF-B will exhibit cross-reactive binding on thereceptor level and thus display identical or similar biologicalactivities.

EXAMPLE 7

Exon-intron Structures of Mouse and Human VEGF-B Genes

The structure of the human VEGF-B gene was determined by restrictionmapping and nucleotide sequence analysis of cloned PCR fragmentsobtained from PCR reactions employing human genomic DNA as the template,except in the case of the first exon and intron, which were identifiedfrom a genomic λ-clone. The structure of the mouse gene was determinedby restriction mapping and nucleotide sequence analysis of cloned PCRfragments amplified using different combinations of primers. As atemplate in these PCR amplifications an isolated genomic λ clonecontaining the entire mouse VEGF-B gene was used.

Procedure.

Several λ clones for the mouse VEGF-B gene were isolated from a 129/SwλFIX genomic library as recommended by the supplier (Stratagene, Inc.).The ≈0.9 kb SalI/NotI insert of the pcif2 cDNA for VEGF-B (SEQ ID NO:1)was used as the probe. λ DNA from several positive clones were isolatedfrom plate lysates. One of the positive λ-clones (clone 10) wassubcloned as BamH1 fragments into pBluescript SK (Stratagene Inc.).Isolated DNA from this same clone was also used as the template in PCRreactions (100 ng of λ DNA/reaction) and the coding parts of the mouseVEGF-B gene were amplified using different combinations of primers. Thenucleotide sequences of these primers were derived from the cDNA clonesencoding murine VEGF-B₁₆₇ and murine VEGF-B₁₈₆. Taq DNA polymerase (2.5U/reaction) was used. The generated PCR fragments were directly clonedinto the TA-cloning vector pCR II (Invitrogen Inc.). The exon-intronstructure of the mouse VEGF-B gene was established by nucleotidesequence analysis of the subcloned Bam H1 genomic fragments and of thecloned PCR products.

A human genomic λ-clone was isolated by screening 1×10⁶ clones of ahuman genomic library in EMBL-3 SP6/T7 (Clontech) using high stringencyconditions with a 90 bp PCR-fragment spanning 5′ sequences of humanVEGF-B cDNA as the probe. The washing conditions were: one wash at 1×SSCat room temperature for 30 minutes and two washes at 1×SSC at 65° C. for30 minutes. Primers for the PCR were:

5′-CACCATGAGCCCTCTGCTCC-3′ (forward) (SEQ ID NO:18) and

5′-GGGCATCAGGCTGGGAGACAG-3′ (reverse) (SEQ ID NO:19).

The positive λ-clone was subcloned as SacI fragments into pGEM 3Z vector(Promega) and was found to carry the 5′-region of the gene. Theremaining parts of the human VEGF-B gene were amplified by PCR usinggenomic DNA as the template. Different combinations of primers derivedfrom the human cDNA sequence were used. Dynazyme DNA polymerase (2.5U/reaction, Finnzymes) was used. The amplified PCR fragments weredirectly cloned into the TA-cloning vector pCR II (Invitrogen Inc.). Theexon-intron boundaries and the length of the short introns of the mouseand human VEGF-B genes were determined by nucleotide sequence analysisusing vector specific primers or suitable primers derived from the cDNAsequences. The length of the larger introns were calculated based on thelength of the amplified PCR fragments when analyzed by agarose gelelectrophoresis.

Results.

The results showed that the coding parts of the mouse and human VEGF-Bgenes span approximately 4 kb of DNA and both genes are divided intoseven coding exons ranging from 19 bp (E7) to 236 bp in length (E6).FIG. 17 is a schematic representation of the structures of the mouse andhuman genes for VEGF-B. The exon sizes in base pairs are noted insidethe boxes, and the sizes of the introns are noted between the boxes. Theintrons are not shown to scale. The structures of the untranslatedflanking regions of mouse and human VEGF-B genes were not establishedand are represented by gray boxes. The exon-intron junctions in bothgenes are listed in the following Table 3:

TABLE 3 Intron Length Exon Length Donor Site (bp) Acceptor Site Mouse E160 T CGC ACC CAG/gtacgtgcgt ≈590 tttcccacag/GCC CCT GTG T a Arg Thr Gln           Ala Pro Val S E2 43 CAG AAG AAA G/gtaataatag  287ctgcccacag/TG GTG CCA TG Gln Lys Lys V            al Val Pro Tr E3 197 CCGA ATG CAG/gtaccagggc  161 ctgagcacag/ATC CTC ATG A l Arg Met Gln           Ile Leu Met I E4 74 GT GAA TGC AG/gtgccagcca  178ctcctcctag/G GTT GCC ATA ys Glu Cys Ar            g Val Ala IlemVEGF-B₁₈₆ E5 36 AG CCA GAC AG/gtgagttttt ≈200 ctcctcctag/G GTT GCC ATAys Pro Asp Ar            g Val Ala Ile E6A 211 Stop codon in exon 6 —   — (TAG) mVEGF-B₁₆₇ E5 36 AG CCA GAC AG/gtgagttttt ≈300 cccactccag/CCCC AGG ATA ys Pro Asp Se            r Pro Arg Ile E6B 135 AC ACC TGTAG/gtaaggagtc ≈2.6 kb cactccccag/G TGC CGG AAG sp Thr Cys Ar           g Cys Arg Lys E7 19 Stop codon in exon 7 —    — (TGA) HumanE1 60 C CCC GCC CAG/gtacgtgcgg ≈760 tctcccacag/GCC CCT GTC T a Pro AlaGln            Ala Pro Val S E2 43 CAG AGG AAA G/gtaatactta  275ctgctcccag/TG GTG TCA TG Gln Arg Lys V            al Val Ser Tr E3 197 CCGG ATG CAG/gtactgggca  244 ctgagcacag/ATC CTC ATG A l Arg Met Gln           Ile Leu Met I E4 74 GT GAA TGC AG/gtgccagcca ≈710tacttttcag/A CCT AAA AAA ys Glu Cys Ar            g Pro Lys LyshVEGF-B₁₈₆ E5 36 AG CCA GAC AG/gtgagtcttt  200 tcctccctag/G GCT GCC ACTys Pro Asp Ar            Ala Ala Thr E6A 211 Stop codon in exon 6 —    —(TAG) hVEGF-B₁₆₇ E5 36 AG CCA GAC AG/gtgagtcttt ≈300 cccactccag/C CCCAGG CCC ys Pro Asp Se            r Pro Arg Pro E6B 135 AC ACC TGCAG/gtaggtttgg  736 ccctcctcag/G TGC CGG AAG sp Thr Cys Ar            gCys Arg Lys E7 19 Stop codon in exon 7 —    — (TGA)

As previously stated, exon 6 contains an alternative splice acceptorsite which enables the gene to produce two different transcripts forVEGF-B isoforms. VEGF-B₁₆₇ uses exons 1-5, the last part of exon 6, andexon 7 (TGA). VEGF-B₁₈₆ uses exons 1 through 5, the first part of exon6, and terminates in the last part of exon 6 (TAG). Exon 7 is nottranslated in VEGF-B₁₈₆ since the insertion of the first part of exon 6introduces a frame shift and gives rise to a stop codon in the last partof exon 6. The position of the stop codon (TAG) for VEGF-B₁₈₆ is markedin exon 6B, and the stop codon (TGA) for VEGF-B₁₆₇ is marked in exon 7.

The introns in both genes vary from 161 bp to approximately 2.6 kb. Thelength of each exon and the locations of the splice junctions in the twogenes were identical, and all splice donor and acceptor sites follow thecanonical GT/AG rules, Padgett et al., Annual Rev. of Biochemistry,55:1119-50 (1986). The only notable difference between the mouse and thehuman genes are the length of introns 1, 4 and 6 which are longer in themouse gene. All exon-intron boundaries were found to be conservedbetween VEGF-B and VEGF, but the introns in the VEGF-B genes weregenerally smaller than in the VEGF gene.

The 300 bp-intron after the exon 5 in VEGF-B differs from thecorresponding one in VEGF, which is 3 kb in length and contains analternatively spliced exon found in the transcripts for VEGF₁₈₉ andVEGF₂₀₆, encoding many basic amino acid residues. When this intron inVEGF-B was analyzed more carefully, no exon corresponding to the 6thexon of VEGF could be found. Instead, the 3′ end of this intron and thefollowing exon were found to be identical with the correspondingsequences of the cDNA clones encoding VEGF-B₁₈₆. This is explainable bythe fact that the mRNA for VEGF-B₁₈₆ is formed by use of an alternativesplice acceptor site during mRNA splicing, resulting in an insertion ofa 101 bp intron sequence into these mRNAs.

FIG. 18 shows a comparative hydrophilicity analysis of murine VEGF-B₁₆₇and VEGF-B₁₈₆. The profiles were generated according to Kyle andDolittle using a window of nine (9) residues. As would be expected, thepattern of hydrophilicity/hydrophobicity is essentially identical fromamino acid 1 through amino acid 115. After amino acid 115, thehydrophilicity/hydrophobicity patterns diverge because of the frameshift introduced by the first part of exon 6. Thus, VEGF-B₁₆₇ andVEGF-B₁₈₆ can be expected to exhibit both similar and dissimilaractivities.

FIG. 19 is a dendrogram showing the phylogenetic relationship of theamino acid sequences of five members of the VEGF/PDGF family of growthfactors. The number of replacements or substitutions decreases from theleft to the right of the chart. It can be seen that VEGF-B lies betweenVEGF and the platelet derived growth factor (PDGF) group.

The multiple amino acid sequence alignments of FIGS. 9 and 16 and thephylogenetic analysis of FIG. 19 were carried out accoring to Hein,Methods in Enzymology, Vol. 183, pp. 626-45, Academic Press Inc., SanDiego (1990) using the PAM 250 distance table.

EXAMPLE 8

Antibody Production

a. Antiserum to Mouse VEGF-B.

Antisera to mouse VEGF-B were raised by immunizing rabbits with a 18-meroligopeptide comprising the N-terminal region of processed VEGF-B,coupled to keyhole limpet hemocyanin. Cysteine residues were introducedas the N-terminal and C-terminal amino acid residues to allow couplingof the peptide to the carrier protein using SPDP (Pharmacia). Thesequence of the oligopeptide was

C-P-V-S-Q-F-D-G-P-S-H-Q-K-K-V-V-P-C (SEQ ID NO:21).

Each rabbit received a subcutaneous injection with 300 μg of the peptideconjugate emulsified in Complete Freunds Adjuvant. Subcutaneous boosterinjections were given every second week with the same amount of antigenemulsified in Incomplete Freunds Adjuvant. Sera were obtained after thesecond booster injections.

b. Antiserum to Human VEGF-B.

Antipeptide antiserum to human VEGF-B was generated by immunizingrabbits with a branched 23-mer oligopeptide comprising the followingN-terminal region amino acid residue sequence (SEQ ID NO:22):

S-Q-P-D-A-P-G-H-Q-R-K-V-V-S-W-I-D-V-Y-T-R-A-T.

The branched 23-mer oligo peptide was synthesized according to Tam,“Synthetic peptide vaccine design: synthesis and properties of ahigh-density multiple antigenic peptide system”, Proc. Natl. Acad. Sci.USA, Vol. 85, pages 5409-413 (1988). In the first immunization, rabbitswere subcutaneously injected with 500 μg of the branched peptideemulsified in Complete Freunds Adjuvant. In the subsequent boosters, 200μg of the antigen emulsified in Incomplete Freunds Adjuvant wasinjected. Antisera were collected after the second and third boosters byconventional techniques.

EXAMPLE 9

Biochemical Properties of VEGF-B₁₆₇, Homo-dimerization, andHeterodimerization with VEGF

The biochemical properties of human VEGF-B₁₆₇ were examined intransfected human embryonic kidney 293EBNA cells (Invitrogen, Inc.).cDNA inserts encoding human VEGF-B₁₆₇ and human VEGF₁₆₅ [see Keck etal., Science, Vol. 246, pages 1309-312 (1989)] were individually clonedinto the pREP7 expression vector (Invitrogen, Inc.). Human embryo kidney293EBNA cells (expressing Epstein-Barr virus nuclear antigen-1) weretransfected by transient transfection with the respective expressionplasmids using calcium phosphate precipitation, and the cells wereincubated for 48 hours. As a control, cells also were transfected withan expression vector containing the VEGF-B₁₆₇ cDNA in reverseorientation. Monolayers of cells were incubated in methionine-free andcysteine-free medium for 30 minutes followed by labeling with 100 μCi/ml[³⁵S]methionine and [³⁵S]cysteine (Promix, Amersham Inc.) in the samemedium for 2 hours. The labeling medium was replaced with normal mediumwithout serum, and labelled proteins were chased for 6 hours. Heparinwas included during the chase when indicated (100 μg/ml). Media werecollected after the chase period, and cells were solubilized in 10 mMTris pH 7.5, 50 mM NaCl, 0.5% sodium deoxycholate, 0.5% Nonidet P-40,0.1% SDS and 0.1 U/ml aprotinin.

VEGF-B₁₆₇ was expressed in the cells transfected with the plasmidscontaining the VEGF-B₁₆₇ DNA. Aliquots of the culture supernatants fromcells treated or untreated with heparin and detergent solubilized celllysates were subjected to immunoprecipitation with the specificantipeptide antiserum to VEGF-B obtained as described in Example 8 andanalyzed by SDS-PAGE under reducing conditions unless otherwiseindicated. The data show that VEGF-B₁₆₇ homodimers and VEGF-B₁₆₇-VEGF₁₆₅heterodimers are released from cells by heparin. By heparin treatment(1-100 μg/ml) or 1.2 M NaCl, VEGF-B₁₆₇ was released from cells and foundin the supernatant. If cells were not treated with heparin, VEGF-B₁₆₇remained cell-associated and was not released into the culture medium.Under the same conditions, VEGF₁₆₅ homodimers are secreted from thecells and found in the culture supernatants without heparin treatment.

Under reducing conditions, human VEGF-B₁₆₇ migrated with a Mr of 21 kDa.Analysis of culture supernatants under non-reducing conditions showedthat VEGF-B₁₆₇ migrated as an Mr 42 kDa species indicating a dimericstructure. These results suggest that VEGF-B₁₆₇ forms disulfide-linkeddimers associated with the cell surface, probably through ionicinteractions with extracellular heparan sulfate proteoglycans. Theassociation is likely to be mediated by the C-terminal basic domain, asobserved for the longer splice variants of VEGF.

Since VEGF has been shown to form heterodimers with PlGF, it was decidedto test whether VEGF₁₆₅ could also form heterodimers with VEGF-B₁₆₇. Forthis purpose 293EBNA cells were co-transfected with expression vectorsencoding both human VEGF₁₆₅ and human VEGF-B₁₆₇, and VEGF-B₁₆₇ wasexpressed in combination with VEGF₁₆₅. Metabolically labelled proteinswere chased in the presence of heparin, and immunoprecipitations werecarried out with antisera to either VEGF-B₁₆₇ or VEGF₁₆₅. The antiserumto human VEGF was from R&D Systems. Under non-reducing conditions theVEGF-B₁₆₇.VEGF₁₆₅ heterodimers migrated as Mr 42-46 kDa species. Theresults show that VEGF-B can form disulfide linked heterodimers withVEGF, which, in the absence of heparin, remain cell-associated. Sincehomodimers of VEGF₁₆₅ are efficiently secreted into the media, VEGF-Bappears to determine the secretion of the heterodimer.

VEGF-B is synthesized normally in the endoplasmic reticulum of thesource cell for subsequent export. Recombinant VEGF-B may be produced byinserting a DNA sequence encoding the VEGF-B protein together withsuitable operatively linked promoter and control sequences into asuitable vector, such as the well known plasmid pBR322 or a derivativethereof, transforming or transfecting a suitable host cell, such as E.coli or a Cos cell, with the resulting vector or other systems wellknown in the art, screening the resulting transformants or transfectantsfor VEGF-B expression, and then culturing cell lines or bacterial cellstrains which are positive for the expression of VEGF-B. Either aeukaryotic vector or a prokaryotic vector may be used, depending on thetype of cell which is to be transfected or transformed therewith. Aparticularly preferred system for production of recombinant VEGF-B isthe baculovirus—insect cell system, which has proved capable ofproducing excellent yields of recombinant protein.

EXAMPLE 10

VEGF-B Expression Using the Baculovirus System

10.1 VEGF-B with its own signal peptide.

a) Cloning and Transfection

The complete human VEGF-B₁₆₇ gene was inserted into a commerciallyavailable plasmid pCRII (Invitrogen Corp.). The HindIII-XbaI fragmentfrom the resulting plasmid pCRII-VEGF-B₁₆₇, which encodes the whole openreading frame of VEGF-B₁₆₇ then was cloned into pFASTBAC1, and both the3′- and 5′-junctions were sequenced. Bacmid-DNA was prepared accordingto the manufacturers instructions for the “Bac-To-Bac™ BaculovirusExpression System” (Life Technologies Inc.) and lipofected toSf900II-adapted Sf9 cells (obtained from Dr. Christian Oker-Blom). Sf9cells are from the American Type Culture Collection Cell Repository LineBank, Rockville Md. (ATCC CRL-1711). The transfected cells were thencultured on standard TMN-FH medium in 25 cm² culture dishes.

b) Assay for Protein Expression

About 72 hours after transfection, the cells were lysed and 1 ml ofculture supernatant and the cell lysate were assayed for expressedVEGF-B by immunoprecipitation as described in Example 9 and Westernblotting. Lysates from three out of four independently transfected cellcultures were found positive for VEGF-B, although the intensity of thesignal in the Western blot varied. The expressed VEGF-B polypeptide ineach case was found to correspond in size to the protein expressed inmammalian cells in Example 9.

The viral stock from the cells that gave the strongest signal in Westernblotting was amplified two rounds by infecting cells and collecting newvirus from the medium. The resulting supernatant was analyzed.Uninfected cells were also analyzed as a negative control. Time courseanalysis showed that cells harvested between 48 and 72 hours afterinfection contained the greatest amount of VEGF-B. After 96 hours postinfection, as a result of virus-induced cell lysis, VEGF-B could also bedetected in the culture supernatant by immunoprecipitation and Westernblotting. Recombinant VEGF-B could be precipitated from the lysatebetween 20% and 40% (NH₄)₂SO₄.

10.2 VEGF-B with the Melittin signal peptide (pVTBac).

a) Cloning and Transfection

A polymerase chain reaction (PCR) fragment from nucleotide position 68to 141 was used to introduce a BamHI restriction site immediately afterthe signal cleavage site in the plasmid pCRII-VEGF-B₁₆₇ from Example10.1. The BamHI fragment from this modified pCRII-VEGF-B₁₆₇ constructwas cloned into BamHI opened pVTBac [Tessier et al., “Enhanced secretionfrom insect cells of a foreign protein fused to the honeybee mellitinsignal peptide”, Gene, Vol. 98, page 177 (1991)]. Both 3′- and5′-junctions were sequenced. Sf9 cells were cotransfected with theaforedescribed pVTBac vector which contained the human VGEF-B₁₆₇ gene,and with linearized baculovirus DNA (Insectin™, Invitrogen Corp.). Thetransfected cells then were cultured in TMN-FH medium.

b) Assay for Protein Expression

Forty-eight hours after transfection, the supernatant was collected andsubjected to primary screening by immunoprecipitation. Four positiveplaques were isolated.

10.3 A cDNA insert encoding murine VEGF-B₁₈₆ (EcoR1 cut cDNA fragmentfrom a murine VEGF-B₁₈₆ cDNA (SEQ ID NO:12) clone) was cloned intopFASTBAC 1. An EcoR1 cut cDNA fragment from murine VEGF-B₁₆₇ (SEQ IDNO:4) was also cloned into pFASTBAC 1. The resulting plasmids weretransformed into bacteria as described in 10.1 above, and recombinedplasmids were isolated and lipofected into Sf9 and Sf21 cells.Supernatants containing recombinant baculovirus were amplified byseveral rounds of reinfection of Sf21 cells. The final titers of thebaculovirus stocks were determined by plaque titration and found to varybetween 4×10⁸ and 2×10⁹ baculovirus particles per milliliter of stocksupernatant.

EXAMPLE 11

Large Scale Production of Recombinant VEGF-B

Sf21 cells [see Vaughn et al., In Vitro, 13:213-17 (1977)] were infectedwith the baculovirus stocks of Example 10 at a multiplicity of infectionof 10 virus particles per cell. The infected Sf21 cells were grown inroller flasks and seeded at a density of 2×10⁶ cells per ml of serumfree medium (Sf900II, Gibco-BRL) for 96 hours. Culture media and cellswere then harvested. Aliquots of the cell lysates and of the media wereanalyzed by SDS-PAGE. Total protein patterns were visualized by stainingthe gels with Coomassie Brilliant Blue and the presence of expressedVEGF-B isoforms were visualized by immunoblotting using specificantipeptide antibodies to human and mouse VEGF-B as described above inExample 8. The analysis revealed that both human and mouse VEGF-B₁₆₇polypeptides were of the expected sizes of 21.5 kDa. Both proteins wereretained intracellularly in the infected cells and not released into themedium. In contrast, mouse VEGF-B₁₈₆ was readily secreted into themedium in a dimeric form. The VEGF-B₁₈₆ homodimers migrated as a 52-54kDa species which suggested that insect cell produced protein did notundergo the same covalent modification as found for VEGF-B₁₈₆ secretedfrom transfected Cos-1 cells.

EXAMPLE 12

Transfection and Analysis of Cos-1 Cells Expressing VEGF-B₁₈₆

cDNA inserts encoding mouse VEGF-B₁₈₆ and human VEGF₁₆₅ were cloned intothe pSGS expression vector [Green et al., Nucleic Acid Res., 16:369(1988)]. Cos-1 cells were maintained in minimal essential medium (MEM)containing 10% fetal calf serum, 2 mM glutamine and appropriateantibiotics. For transfections, the cells were replated into 90 mm Petridishes. The cells were transfected with the expression vectors,separately or in combination, using calcium phosphate precipitation andincubated for 36-48 hours. Monolayers of cells were incubated in mediumfree of methionine and cysteine for 30 min and then incubated in thesame medium containing 100 μCi/ml of [³⁵S]-methionine and [³⁵S]-cysteinefor 2 hours (Promix Amersham Inc.).

For the pulse-chase experiments, the cells were labeled for 30 minutes,washed twice with normal medium and then incubated for up to 6 hours inMEM without fetal calf serum. Media were collected after the chaseperiod and the cells were solubilized in 10 mM Tris buffer pH 7.5containing 50 mM NaCl, 0.5% deoxycholate, 0.5% nonidet P-40 and 0.1%SDS. Aliquots of the media and the cell lysates were subjected toimmunoprecipitation using the specific antiserum to mouse VEGF-B fromExample 8a and a specific antiserum to human VEGF commercially availablefrom R&D Systems. The precipitates were analyzed by SDS-PAGE.

EXAMPLE 13

Biochemical Properties of VEGF-B₁₈₆ Expressed in Transfected Cos-1 Cells

The biochemical properties of mouse VEGF-B₁₈₆ were examined in Cos-1cells transiently transfected as described in Example 12 with anappropriate expression vector. The cells were metabolically labelled,and proteins from the labelled cells were immunoprecipitated using anantipeptide antibody to VEGF-B. The precipitated material was subjectedto SDS-PAGE analysis under reducing conditions. Both the cell culturemedium (M) and a detergent solubilized cell lysate (L) were analyzed.The results are shown in FIG. 22. It can be seen that cell associatedVEGF-B₁₈₆ migrated as an approximately M_(r) 24,000 polypeptide underreducing conditions. In contrast, VEGF-B₁₈₆ present in the medium oftransfected cells migrated as a M_(r) 32,000 species, suggesting thatthe protein was covalently modified during its intracellular transportand secretion. The corresponding molecules were not detected in celllysates or media from mock transfected Cos-1 cells used as a control.

Immunoprecipitation of media and SDS-PAGE analysis under non-reducingconditions, showed an approximately M_(r) 60,000 species suggesting thatVEGF-B₁₈₆ formed disulfide-linked. homodimers. Including 100 ug/ml ofheparin during the labelling did not affect the secretion or release ofVEGF-B₁₈₆ homodimers from the transfected cells.

EXAMPLE 14

Biosynthesis of VEGF-B₁₈₆ Homodimers

The biosynthesis of VEGF-B₁₈₆ homodimers was examined by pulse-chaseexperiments. Transfected Cos-1 cells were metabolically labelled for 30minutes and then chased for up to 4 hours. Immunoprecipitation andSDS-PAGE analysis of detergent solubilized cell lysates and media showedthat the cell-associated approximately M_(r) 24,000 species was readilydetected in the lysates throughout the chase period. The decrease in theintensity of this molecular species was associated with an increase inthe M_(r) 32,000 protein present in the media. The M_(r) 32,000 speciesappeared in the medium after 1 hour of chase. Highest levels of secretedVEGF-B₁₈₆ were obtained after the 4 hour chase period. No intermediateswere detected in the cell lysates, but the secreted M_(r) 32,000 proteinappeared slightly heterogenous. The nature of the modification ispresently unknown, but N-linked glycosylation can be excluded in theabsence of consensus sites for this modification.

EXAMPLE 15

Formation of Heterodimers by VEGF-B₁₈₆

As noted above, VEGF-B and VEGF are coexpressed in many tissues andVEGF-B₁₆₇·VEGF₁₆₅ heterodimers are readily formed when coexpressed intransfected cells. To examine whether VEGF-B₁₈₆ also could formheterodimers with VEGF₁₆₅, Cos-1 cells were transfected as describedabove with the appropriate expression vectors, either alone or incombination. Metabolically labelled proteins present in the media fromthe transfected cells were subjected to immunoprecipitations usingantisera to VEGF-B and VEGF. FIG. 23A shows the results of SDS-PAGEanalysis under reducing conditions of the immunoprecipitates from thecell culture media of transiently transfected Cos-1 cells separatelyexpressing VEGF-B₁₈₆ and VEGF, respectively. It can be seen that theantisera were specific for VEGF-B and VEGF, respectively, with nodetectable cross-reactivity.

Cos-1 cells were cotransfected with expression vectors for VEGF-B₁₈₆ andVEGF₁₆₅. Cell culture media (M) and detergent solubilized lysates (L)from the resulting cells which coexpressed VEGF-B₁₈₆ and VEGF₁₆₅ weresubjected to immunoprecipitation and SDS-PAGE analysis under reducingconditions. The results are shown in FIG. 23B. The test showed thatmurine VEGF-B₁₈₆ and human VEGF₁₆₅ form intracellular and secretedheterodimers.

Culture media from cells expressing murine VEGF-B₁₈₆ and human VEGF₁₆₅,either separately or in combination, were subjected toimmunoprecipitation using antibodies to VEGF-B and VEGF and analyzed bySDS-PAGE under non-reducing conditions. As a control, cell culturemedium from mock transfected cells was analyzed. The results are shownin FIG. 23C. It was found that VEGF-B₁₈₆ forms secreted disulfide-linkedhomodimers and that VEGF-B₁₈₆ and VEGF₁₆₅ together form secreteddisulfide-linked heterodimers.

To analyze whether heterodimer formation with VEGF affected thesecretion and release of VEGF-B₁₈₆, pulse-chase experiments were carriedout using Cos-1 cells transiently transfected with expression vectorsfor VEGF-B₁₈₆ and VEGF₁₆₅. Cell associated disulfide-linked heterodimerscould be recovered following the 30 minute labelling period, andsecreted heterodimers were recovered from the medium already after a 30minute chase period. The secreted heterodimers accumulated in the mediumfor up to 2 hours post labelling. In the 4 hour chase time point therewas a decrease in the amount of heterodimers in the medium, possibly dueto the degradation of the complex. Some VEGF-B₁₈₆·VEGF heterodimersremained cell-associated throughout the chase. These results suggestedthat heterodimer formation with VEGF promoted the secretion of VEGF-B₁₈₆compared to the secretion of VEGF-B₁₈₆ homodimers. Furthermore, thepresence of heterodimers already following the 30 minute labellingperiod suggested that the slow release of VEGF-B₁₈₆ homodimers was notdue an impaired ability of VEGF-B₁₈₆ to dimerize.

EXAMPLE 16

Purification of Secreted VEGF-B₁₈₆ Homodimers

Secreted VEGF-B₁₈₆ homodimers were isolated from serum free culturemedia of baculovirus infected Sf21 cells as follows:

a. Initial Separation.

The major contaminating protein in the culture media was the baculovirusprotein gp64/67, an acidic protein secreted by baculovirus infectedcells. To remove this protein, the culture media was concentratedtwenty-fold by ultrafiltration and then passed over a Sephadex G-25column equilibrated in 20 mM phosphate buffer pH 6.5 containing 20 mMNaCL. Eluted proteins were then passed over a CM-Sepharose (Pharmacia)ion-exchange column equilibrated in the same buffer. The column waswashed with the phosphate buffer to remove unbound proteins, and boundproteins were eluted by stepwise increasing the NaCl concentration ofthe elution buffer. The major gp64/67 baculovirus encoded protein didnot bind to the ion-exchange column under those conditions whileVEGF-B₁₈₆ homodimers eluted at a NaCl concentration of 90 mM. As judgedby SDS-PAGE analysis of the eluted fraction, VEGF-B₁₈₆ homodimers were5-15% pure by this procedure.

b. Purification to Homogeniety.

The VEGF-B₁₈₆ homodimers are purified to homogeneity on a MonoS columncoupled to a FLPC system (Pharmacia). Bound protein is eluted with alinear gradient of NaCl in 20 mM phosphate buffer pH 6.5.

EXAMPLE 17

In order to find out whether the two VEGF-B splice isoforms exhibited adifferential tissue distribution and whether additional isoformsexisted, an RT-PCR analysis was carried out using total RNA extractedfrom mouse brain, heart, liver and kidney and from human embryonic heartand skeletal muscle. The transcripts were analyzed by PCR using fourpairs of specific primers covering exons 4 to 7 and exons 3 to 7 in themouse and human VEGF-B genes, respectively.

Procedure.

Total RNA from mouse and human tissues were isolated using standardprocedures as disclosed by Chirgwin et al., Biochemistry, 18:5294-99(1979). Two to five μg of total RNA per reaction were used for firststrand cDNA synthesis using avian myelostosis virus reversetranscriptase (20 U/reaction). The reactions were primed witholigo-(dT)₁₈. Aliquots of these reactions were used as templates in PCRreactions using Taq DNA polymerase (2.5 U/reaction). To amplify mousecDNA, two pairs of primers were used. These pairs were obtained bycombining a common 5′-primer

5′-CACAGCCAATGTGAATGCA (forward) (SEQ ID NO:23), located in exon 4 withtwo different 3′-primers 5′-GCTCTAAGCCCCGCCCTTGGCAATGGAGGAA (reverse)(SEQ ID NO:24) and 5′-ACGTAGATCTTCACTTTCGCGGCTTCCG (reverse) (SEQ IDNO:25) (this last primer has a Bgl II site and 4 extra bases in the 5′end) located in exons 6B and 7, respectively. Following analysis byagarose gel electrophoresis, the amplified bands were transferred onto anylon filter (Genescreen Plus) and sequentially hydbridized witholigonucleotide probes specific for exons 6A and 6B. The oligonucleotideprobes were 5′-CTCTGTTCCGGGCTGGGACTCTA (exon 6A) (SEQ ID NO:26) and5′-TCAGGGCGTTGACGGCGCTGGGTGCAA (exon 6B) (SEQ ID NO:27). Theoligonucleotide probes were labeled with [³²P]dCTP using terminaltransferase to high specific activity. Hybridizations, using 1×10⁶ cpmof labeled probe/ml of solution, were carried out at 37° C. in 6×SSCcontaining 5×Denhardt's solution, 0.5% SDS and 100 μg/ml of salmon spermDNA. The filters were washed at the same temperature in 6×SSC containing0.5% SDS for 2×15 min and exposed to film.

The two pairs of primers used for amplification of human cDNA werecombined using two different 5′-primers,

5′-CCTGACGATGGCCTGGAGTGT (forward) (SEQ ID NO:28), located in exon 3 and

5′-TGTCCCTGGAAGAACACAGCC (forward) (SEQ ID NO:29), located in exon 4,with a common 3′-primer,

5′-GCCATGTGTCACCTTCGCAG (reverse) (SEQ ID NO:19) located in exon 7.Aliquots of the amplified products were analyzed by agarose gelelectrophoresis. The aliquots were directly cloned in the TA-cloningvector pCR II (Invitrogen, Inc.), and generated plasmids were analyzedby nucleotide sequencing. Amplification of GAPDH served as a control.

Results.

Analysis of amplified PCR products by agarose gel electrophoresis showedtwo major bands of 215 and 316 bp, respectively. These sizes areconsistent with the two mRNAs corresponding to VEGF-B₁₆₇ and VEGF-B₁₈₆.These two bands were of the same intensity suggesting that the twoisoforms were expressed at approximately equal levels in all mouse andhuman tissues examined.

To verify the identity of the amplified products from mouse tissues, thePCR-amplified DNA was transferred to a filter and probed with specificoligonucleotide probes for exons 6A and 6B, respectively. Theautoradiograms showed that an exon 6-specific probe hybridized with the316 bp band while the exon 6B specific probe hybridized with both the215 bp and the 316 bp amplified bands. These results are consistent withthe alternative usage of acceptor site in exon 6 to create the twoisoforms of VEGF-B and thus all the amplified products corresponded tothose predicted from the sequences of VEGF-B₁₆₇ and VEGF-B₁₈₆ isoforms.

Agarose gel electrophoresis of products of PCR analysis of total RNAisolated from human embryonic heart and muscle visualized two majoramplified bands of 329 bp and 430 bp.

Taken together, these data demonstrate that VEGF-B₁₆₇ and VEGF-B₁₈₆ arethe two major isoforms of VEGF-B in tissues. The pattern of the PCRproducts and the location of the primers indicate that if any stilllonger splice isoforms exist for VEGF-B, such transcripts use a spliceacceptor site located a little more 5′ than in the case of VEGF-B₁₈₆.Furthermore, PCR products corresponding to VEGF₁₂₁, which lacks heparinbinding domains, i.e. sequences corresponding to exon 6 in VEGF-B, werenot detected. However, splicing of exon 5 to exon 7 would give rise to atranscript encoding an isoform of VEGF-B corresponding to VEGF₁₂₁, andthis putative isoform of VEGF-B might be expressed in tissues other thanthose analyzed in this example.

EXAMPLE 18

Stimulation of Cell Proliferation

The ability of VEGF-B₁₆₇ to stimulate endothelial cell proliferation wasestablished through analysis of [³H]thymidine incorporation in humanumbilical vein endothelial cells (HUVEC) and in bovine capillaryendothelial (BCE) cells.

293EBNA cells were transfected as described above with expressionvectors for VEGF-B₁₆₇, VEGF₁₆₅ or empty vector (mock) in the presence of1 μg/ml heparin. Conditioned media from these cells were diluted inrespective media, applied to human umbilical vein endothelial cells(HUVEC) and to bovine capillary endothelial (BCE) cells andincorporation of [³H]thymidine was measured. As a positive controlrecombinant bFGF was added to BCE cells.

To elaborate, conditioned media containing human VEGF-B and humanVEGF₁₆₅ were collected from 293EBNA cells transfected with theappropriate expression vectors or with empty vector (mock) in thepresence of heparin (1 μg/ml) 48 hours posttransfection. Second passageHUVEC were plated into 96-well plates (4×10³ cells/well) in M-199 mediumsupplemented with 10% fetal bovine serum and incubated for 24 hours.Conditioned media were diluted with the growth medium, and cells werestimulated for 48 hours. Fresh conditioned media containing 10 μCi/ml of[³H]thymidine (Amersham Inc.) were added to the cells, and stimulationswere continued for another 48 hours. Cells were washed with PBS andtrypsinized, and incorporated radioactivity was determined by liquidscintillation counting. BCE cells were seeded into 24-well plates andgrown until confluence in minimal essential medium (MEM) supplementedwith 10% fetal calf serum. Cells were starved in MEM supplemented with3% fetal calf serum for 72 hours, after which conditioned media dilutedinto serum-free medium were added to the cells and the cells werestimulated for 24 hours. [³H]Thymidine was included during the last 4hours of the stimulation (1 μCi/ml). Stimulations with bFGF were carriedout as above using 6 ng/ml of recombinant bFGF (Synergen Inc.). Cellswere washed with PBS, lysed with NaOH, and incorporated radioactivitywas determined by liquid scintillation counting.

FIG. 20 is a bar graph showing fold of induction of [³H]thymidineincorporation by VEGF-B₁₆₇ in human umbilical vein endothelial cells(HUVEC) and in bovine capillary endothelial (BCE) cells, as compared tobasal activity induced by conditioned medium from the mock transfectedcells. For comparison purposes, the induction by VEGF₁₆₅ and by bFGF arealso shown. The bars show the mean±standard deviation of parallelsamples. Similar results were obtained in several other independentexperiments. The test results clearly show that VEGF-B induced[³H]thymidine incorporation in both HUVEC and BCE cells and stimulatedproliferation of endothelial cells in vitro, thereby demonstrating thatVEGF-B is an endothelial growth factor.

EXAMPLE 19

Identification of Human VEGF-B Promoter DNA Clones and Activity

A human genomic DNA library in bacteriophage λ EMBL was screened using a5′ PCR fragment containing the sequences from the VEGF-B first andsecond exons as a probe. Two positive clones were obtained, and one ofthese was subcloned in the Bluescript SKII plasmid as Sac I fragments. A1.4 kb fragment was obtained, which contained about 0.4 kb of sequencesupstream from an Nco I site present in the cDNA (located less than 100bp upstream of the ATG translational initiation site).

In addition, an XhoI fragment of about 6 kb from the other λ clone wassubcloned into the pGEMEX plasmid. This subclone contained about 1.5 kbof sequences upstream from the NcoI site. The SacI/NcoI fragment and anEcoRI (polylinker)—NcoI fragment were subcloned into pGL3 basic vector(Promega) in the respective transcriptional orientation. DNA of thesesubclones, and from the pGL3 control vector containing the SV40promoter, was transfected into HeLa cells using calcium phosphateprecipitation. Two days after transfection, the luciferase activitieswere measured from lysates of the transfected cells. The resultsindicated that the 400 bp SacI/NcoI fragment has promoter activity equalto about 30% of the activity of the pGL3 control vector, while the 1.5kb fragment gave only background activity. Use of a stronger or moreactive promoter, for example the CMV promoter or the elongation factor1-alpha promoter, would probably give higher activity in human cells andtissues. The structure of the cloned fragments is illustrated in FIG.24.

The 1.5 kb fragment upstream of the Nco I site was sequenced. Theresulting sequence (SEQ ID NO:17) is illustrated in FIG. 25. Thesequence obtained revealed a putative silencer element [Weissman andSinger, Molecular and Cellular Biology, 11:4228-234 (1991)] composed oftwo eight-base pair stretches between nucleotides 166-187 (boxed in thedrawing). This silencer may be responsible for the relative lack ofactivity of the 1.5 kb fragment.

EXAMPLE 20

Analysis of VEGF-B mRNA in Melanomas, Normal Skin and Muscle by RT-PCR

Normal skin and melanoma tissues were obtained from patients attendingthe Department of Radiotherapy and Oncology, Helsinki University CentralHospital. Four metastatic melanoma specimens were obtained freshly aftersurgical excision, immediately embedded in Tissue-tek (Miles) and frozenin liquid nitrogen. Samples of normal skin were obtained from volunteerpatients undergoing surgery for mammary carcinoma and excision of acutaneous naevus. All specimens were inspected by a pathologist toconfirm the diagnosis.

Total RNA was isolated by the guanidium isothiocyante procedure[Chomczynski et al., Anal. Biochem. 162:156-159 (1987)]. cDNA wassynthesized using 0.2 μg of random hexadeoxynucleotide primers, 5 unitsof murine reverse transcriptase, 5 μg of total RNA as a template and afirst-strand cDNA synthesis kit (Pharmacia). After incubation at 37° C.for 1 hour, the reaction mixture was stored at −70° C. Negative controlsamples for PCR amplification were prepared similarly except thatreverse transcriptase was not added. β-actin also was tested as aninternal standard because it is expressed at a constitutive high level,and its expression does not show much variation in different cells.

For PCR amplification, the primer sequences were selected from theVEGF-B and β-actin genes as follows:

VEGF-B sense: 5′-GCCATGTGTCACCTTCGCAG-3′ (SEQ ID NO:19)

VEGF-B antisense: 5′-TGTCCCTGGAAGAACACAGCC-3′ (SEQ ID NO:29)

β-actin sense: 5′-CGGGAAATCGTGCGTGACAT-3′ (SEQ ID NO:30)

β-actin antisense: 5′-GGAGTTGAAGGTAGTTTCGTG-3′ (SEQ ID NO:31)

[β-actin sequences comprise nucleotides 2105-2125 and 2411-2432 from Nget al., Mol. Cell Biol. 5:2720-732 (1985)]. An aliquot of 4 μl from thecDNA reaction product was heated to 94° C. for 5 minutes and used as atemplate for PCR amplification with 20 pmol of primers, 10×PCR buffer, 1μl of 20 mM dNTPs and 2.5 U of Taq polymerase. Final volume was adjustedto 100 μl with DEPC treated water. Denaturation was at 95° C. for 1minute, annealing at 62° C. for 45 seconds, and polymerization at 72° C.for 50 seconds, for a total of 35 cycles for VEGF-B and 25 cycles forβ-actin. After every 5 cycles, 15 μl aliquots were taken for analysis.

Electrophoresis of 5 μl of the PCR reaction mix was performed in a 2%agarose gel containing ethidium bromide. The size marker DNA fragmentsranged in length from 24 to 726 base pairs (ΦX174 DNA/Hinf I marker fromPromega, Madison, Wis., USA). The tested samples thus included fourmetastatic melanomas, muscle, normal skin, a negative control (withoutreverse transcriptase), and the ΦX174 DNA/Hinf I size marker. Theresults of the RT-PCR analysis for VEGF-B (PCR product lengths 323 and234 bp) and for β-actin show that VEGF-B is highly expressed in allmelanomas studied, at levels approximately similar to the expression inmuscle tissue. On the other hand, normal skin has very little of theVEGF-B RNA. Similar conclusions can be drawn from Northern blotting andhybridization analysis.

The foregoing results indicate that that VEGF-B is a novel growth factorfor endothelial cells which plays a role in vascularization, inparticular of muscle. Collateral artery growth in ischemic heart or limbmay be promoted by arterial administration of a VEGF-B bolus usingtechniques described by Takeshita et al., Am. J. Pathol., 147:1649-60(1995). The cell-association of VEGF-B may have several implications forregulation of vascularization and endothelial cell growth. In developingembryos and in contractile tissues, cell-associated VEGF-B may providespatial cues to outgrowing endothelial cells during establishment andmaintenance of the vascular tree. It could also, through itscell-association, support the regeneration of damaged endothelium inadult vessels. Reendothelialization of arterial injury may be promotedby direct application of VEGF-B using techniques described by Asahara etal., Circulation, 91(11):2793-802 (1995). The ability of VEGF-B tomodulate the secretion of VEGF by heterodimer formation suggests anindirect role of VEGF-B in VEGF signalling, thereby regulating receptorbinding and/or activation as described by Potgens et al., J. Biol.Chem., 269(52):32879-85 (1994). The formation of multiple heterodimericcomplexes of these growth factors could provide a basis for a diversearray of regulatory signals for endothelial cells.

VEGF-B can be used as a growth factor for populations of endothelialcells in vitro. VEGF-B may be used to promote desirable angiogenesis,i.e. the formation of new blood vessels and capillaries; see Takeshitaet al., supra. For example, it may be useful in promoting thedevelopment of the corpus luteum and endometrium as an aid to initiatingand/or maintaining pregnancy. It would also be useful in bone repair byvirtue of its action on endothelial cells. Administration of VEGF-B mayalso be useful in supporting embryogenesis, as well as somatic growthand vascular development and differentiation. Topical application ofVEGF-B to wounds may be useful in promoting wound healing, and oraladministration of VEGF-B may be useful to accelerate the healing ofgastric and/or duodenal ulcers. The ability of VEGF-B to modulate thesecretion of VEGF by heterodimer formation could provide a therapeuticrole for VEGF-B in diseases where VEGF agonists would be useful; seePotgens et al., supra.

VEGF-B may exert proliferative effects on mesodermal cells eitherdirectly or via improvements in the blood supply.

VEGF-B has been found to be overexpressed in tumors, such as melanomas.Consequently, assays for VEGF-B expression can be used as tools in tumordiagnosis, and suppression of VEGF-B expression, for example withmonoclonal antibodies, may be useful to retard tumor growth.

Tumor assays for VEGF-B may be useful as indicators of metastatic risk.For example, use of VEGF-B antibodies analogous to the proceduresdescribed by Takahashi et al., Cancer Res., 55:3964-68 (1995) in orderto quantitate neovascularization and proliferation could be used as anindicator of metastatic risk from colon cancer. Assays of VEGF-B in bodyfluids or the tumor itself by histochemistry may be useful as a tumorprognostic factor. An ELISA analogous to the procedure described byKondo et al., Biochemica et Biophysica Acta, 1221(2):211-14 (1994) maybe useful to detect VEGF-B upregulation as a tumor screen. An enzymelinked immunoabsorbent assay of VEGF-B expression using techniquesdescribed by Boocock et al., J. Natl. Cancer Inst., 87:506-16 (1995) maybe useful as a diagnostic index of ovarian cancer. An assay of VEGF-Bexpression similar to the VEGF assay described by Weindel et al.,Neurosurgery, 35:439-48 (1994) may be useful as an indicator ofmalignancy in brain tumors.

Furthermore, because tumor growth requires angiogenesis, administrationof VEGF-B may also be useful in promoting tumor growth in laboratoryanimals in order to test anti-tumorigenic drugs. VEGF-B may also beuseful to increase the microvascularity of hypoxic areas of tumors andmake them more sensitive to radiation, radiation sensitizing drugs, etc.

The angiogenic action of VEGF-B may be useful in treating ischemicconditions. Administration of an intra-arterial bolus of VEGF-B by thetechniques described in Bauters et al., American Journal of Physiology,267(4 Pt 2):H1263-71 (1994) may be useful to treat lower extremityischemia and increase perfusion in the extremities. Using proceduresdescribed by Mesri et al., Circulation Research, 76:161-67 (1995) anangiogenic response may be produced in tissue injected with fibroblastcells transduced with a virus which expresses VGEF-B in order to treattissue ischemia (e.g. myocardial ischemia). VEGF-B or agonists could beused to stimulate the development of collateral circulation in cases ofarterial and/or venous obstruction, e.g. myocardial infarcts, ischaemiclimbs, deep venous thrombisis, and/or postpartum vascular problems; seeTakeshita et al, supra.

A VEGF-B/VEGF-B receptor system may be used as an assay system to detectsmall molecules as agonists/antagonists for development as new drugs.Examples of small molecules which could be detected include, but are notlimited to, organic chemicals, peptides, and RNA molecules.

Pharmaceutical compositions may be produced by admixing apharmaceutically effective amount of VEGF-B protein with one or moresuitable carriers or adjuvants such as water, mineral oil, polyethyleneglycol, starch, talcum, lactose, thickeners, stabilizers, suspendingagents, etc. Such compositions may be in the form of solutions,suspensions, tablets, capsules, creams, salves, ointments, or otherconventional forms.

As demonstrated in Example 7, VEGF-B protein also can be used to produceantibodies. In general, conventional antibody production techniques maybe used to produce VEGF-B antibodies. For example, specific monoclonalantibodies may be produced via immunization of fusion proteins obtainedby recombinant DNA expression.

Labelled monoclonal antibodies, in particular, should be useful inscreening for conditions associated with abnormal levels of VEGF-B inthe body. For example, an assay of VEGF-B in synovial fluids and/orjoint tissue by immunofluorometric techniques analogous to the theprocedure described by Fava et al., Journal of Experimental Medicine,180:341-46 (1994) may be useful as a diagnostic indicator of rheumatoidarthritis. A radioimmunoassay of VEGF-B in occular fluid usingtechniques described by Aiello et al., in New England Journal ofMedicine, 331(22):1480-87 (1994) may be useful as a diagnostic indicatorof diabetic retinopathy, neovascularization of the iris or retinal veinocclusion. Immunoassays of VEGF-B levels in blood, urine or other bodilyfluids may be useful also as a tumor marker; see Kondo et al., supra.These monoclonal antibodies to VEGF-B also may be useful in inhibitingangiogenesis associated with high levels of VEGF-B in the body, e.g. inrapidly proliferating, angiogenesis-dependent tumors in mammals, andthereby may retard the growth of such tumors. Treatment with amonoclonal antibody specific for VEGF-B using techniques analogous tothose described by Kim et al., in Nature, 362(6243):841-44 (1993) may beuseful to suppress or inhibit tumor growth in vivo. Intravenous and/orsubcutaneous injection of monoclonal antibodies to VEGF-B usingprocedures like those described by Asano et al., in Cancer Research,55:5296-5301 (1995) may be useful to inhibit neovascularization andprimary and metastatic growth of solid tumors. For the therapy ofhumans, chiaserization or humanization of such monoclonal antibodies isto be preferred. Treatment may be effected, e.g., by twice weeklyintraperitoneal injection of 10 to 500 μg, preferably 50-100 μg ofmonoclonal antibody.

VEGF-B antagonists such as antibodies also may be useful to inhibit newblood vessels in diabetic retinopathy, psoriasis, arthopathies and/orvascular tumors such as haemangiomas; see Aiello et al., supra.

The foregoing description and examples have been set forth merely toillustrate the invention and are not intended to be limiting. Sincemodifications of the disclosed embodiments incorporating the spirit andsubstance of the invention may occur to persons skilled in the art, theinvention should be construed to include everything within the scope ofthe appended claims and equivalents thereof.

57 886 base pairs nucleic acid single linear cDNA NO not provided mouseembryo pcif2 1 CGGGACGCCC AGTGGTGCCA TGGATAGACG TTTATGCACG TGCCACATGCCAGCCCAGGG 60 AGGTGGTGGT GCCTCTGAGC ATGGAACTCA TGGGCAATGT GGTCAAACAACTAGTGCCCA 120 GCTGTGTGAC TGTGCAGCGC TGTGGTGGCT GCTGCCCTGA CGATGGCCTGGAATGTGTGC 180 CCACTGGGCA ACACCAAGTC CGAATGCAGA TCCTCATGAT CCAGTACCCGAGCAGTCAGC 240 TGGGGGAGAT GTCCCTGGAA GAACACAGCC AATGTGAATG CAGACCAAAAAAAAAAAGGA 300 GAGTGCTGTG AAGCCAGACA GCCCCAGGAT CCTCTGCCCG CCTTGCACCCAGCGCCGTCA 360 ACGCCCTGAC CCCCGGACCT GCCGCTGCCG CTGCAGACGC CGCCGCTTCCTCCATTGCCA 420 AGGGCGGGGC TTAGAGCTCA ACCCAGACAC CTGTAGGTGC CGGAAGCCGCGAAAGTGACA 480 AGCTGCTTTC CAGACTCCAC GGGCCCGGCT GCTTTTATGG CCCTGCTTCACAGGGACGAA 540 GAGTGGAGCA CAGGCAAACC TCCTCAGTCT GGGAGGTCAC TGCCCCAGGACCTGGACCTT 600 TTAGAGAGCT CTCTCGCCAT CTTTTATCTC CCAGAGCTGC CATCTAACAATTGTCAAGGA 660 ACCTCATGTC TCACCTCAGG GGCCAGGGTA CTCTCTCACT TAACCACCCTGGTCAAGTGA 720 GCATCTTCTG GCTGGCTGTC TCCCCTCACT ATGAAAACCC CAAACTTCTACCAATAACGG 780 GATTTGGGTT CTGTTATGAT AACTGTGACA CACACACACA CTCACACTCTGATAAAAGAG 840 AACTCTGATA AAAGAGATGG AAGACACTAA AAAAAAAAAA AAAAAA 886102 amino acids amino acid single linear protein NO not provided mouseembryo 2 Gly Arg Pro Val Val Pro Trp Ile Asp Val Tyr Ala Arg Ala Thr Cys1 5 10 15 Gln Pro Arg Glu Val Val Val Pro Leu Ser Met Glu Leu Met GlyAsn 20 25 30 Val Val Lys Gln Leu Val Pro Ser Cys Val Thr Val Gln Arg CysGly 35 40 45 Gly Cys Cys Pro Asp Asp Gly Leu Glu Cys Val Pro Thr Gly GlnHis 50 55 60 Gln Val Arg Met Gln Ile Leu Met Ile Gln Tyr Pro Ser Ser GlnLeu 65 70 75 80 Gly Glu Met Ser Leu Glu Glu His Ser Gln Cys Glu Cys ArgPro Lys 85 90 95 Lys Lys Arg Arg Val Leu 100 55 amino acids amino acidsingle linear protein NO not provided mouse embryo 3 Lys Pro Asp Ser ProArg Ile Leu Cys Pro Pro Cys Thr Gln Arg Arg 1 5 10 15 Gln Arg Pro AspPro Arg Thr Cys Arg Cys Arg Cys Arg Arg Arg Arg 20 25 30 Phe Leu His CysGln Gly Arg Gly Leu Glu Leu Asn Pro Asp Thr Cys 35 40 45 Arg Cys Arg LysPro Arg Lys 50 55 565 base pairs nucleic acid single linear cDNA NO notprovided adult mouse heart 4 GAGCCCCCTG CTCCGTCGCC TGCTGCTTGT TGCACTGCTGCAGCTGGCTC GCACCCAGGC 60 CCCTGTGTCC CAGTTTGATG GCCCCAGCCA CCAGAAGAAAGTGGTGCCAT GGATAGACGT 120 TTATGCACGT GCCACATGCC AGCCCAGGGA GGTGGTGGTGCCTCTGAGCA TGGAACTCAT 180 GGGCAATGTG GTCAAACAAC TAGTGCCCAG CTGTGTGACTGTGCAGCGCT GTGGTGGCTG 240 CTGCCCTGAC GATGGCCTGG AATGTGTGCC CACTGGGCAACACCAAGTCC GAATGCAGAT 300 CCTCATGATC CAGTACCCGA GCAGTCAGCT GGGGGAGATGTCCCTGGAAG AACACAGCCA 360 ATGTGAATGC AGACCAAAAA AAAAGGAGAG TGCTGTGAAGCCAGACAGCC CCAGGATCCT 420 CTGCCCGCCT TGCACCCAGC GCCGTCAACG CCCTGACCCCCGGACCTGCC GCTGCCGCTG 480 CAGACGCCGC CGCTTCCTCC ATTGCCAAGG GCGGGGCTTAGAGCTCAACC CAGACACCTG 540 TAGGTGCCGG AAGCCGCGAA AGTGA 565 188 aminoacids amino acid single linear protein NO not provided adult mouse heart5 Met Ser Pro Leu Leu Arg Arg Leu Leu Leu Val Ala Leu Leu Gln Leu 1 5 1015 Ala Arg Thr Gln Ala Pro Val Ser Gln Phe Asp Gly Pro Ser His Gln 20 2530 Lys Lys Val Val Pro Trp Ile Asp Val Tyr Ala Arg Ala Thr Cys Gln 35 4045 Pro Arg Glu Val Val Val Pro Leu Ser Met Glu Leu Met Gly Asn Val 50 5560 Val Lys Gln Leu Val Pro Ser Cys Val Thr Val Gln Arg Cys Gly Gly 65 7075 80 Cys Cys Pro Asp Asp Gly Leu Glu Cys Val Pro Thr Gly Gln His Gln 8590 95 Val Arg Met Gln Ile Leu Met Ile Gln Tyr Pro Ser Ser Gln Leu Gly100 105 110 Glu Met Ser Leu Glu Glu His Ser Gln Cys Glu Cys Arg Pro LysLys 115 120 125 Lys Glu Ser Ala Val Lys Pro Asp Ser Pro Arg Ile Leu CysPro Pro 130 135 140 Cys Thr Gln Arg Arg Gln Arg Pro Asp Pro Arg Thr CysArg Cys Arg 145 150 155 160 Cys Arg Arg Arg Arg Phe Leu His Cys Gln GlyArg Gly Leu Glu Leu 165 170 175 Asn Pro Asp Thr Cys Arg Cys Arg Lys ProArg Lys 180 185 591 base pairs nucleic acid single linear cDNA NO notprovided adult mouse heart 6 ACCATGAGCC CCCTGCTCCG TCGCCTGCTG CTTGTTGCACTGCTGCAGCT GGCTCGCACC 60 CAGGCCCCTG TGTCCCAGTT TGATGGCCCC AGCCACCAGAAGAAAGTGGT GCCATGGATA 120 GACGTTTATG CACGTGCCAC ATGCCAGCCC AGGGAGGTGGTGGTGCCTCT GAGCATGGAA 180 CTCATGGGCA ATGTGGTCAA ACAACTAGTG CCCAGCTGTGTGACTGTGCA GCGCTGTGGT 240 GGCTGCTGCC CTGACGATGG CCTGGAATGT GTGCCCACTGGGCAACACCA AGTCCGAATG 300 CAGGTACCAG GGCCTATGGG TCAGATCCTC ATGATCCAGTACCCGAGCAG TCAGCTGGGG 360 GAGATGTCCC TGGAAGAACA CAGCCAATGT GAATGCAGACCAAAAAAAAA GGAGAGTGCT 420 GTGAAGCCAG ACAGCCCCAG GATCCTCTGC CCGCCTTGCACCCAGCGCCG TCAACGCCCT 480 GACCCCCGGA CCTGCCGCTG CCGCTGCAGA CGCCGCCGCTTCCTCCATTG CCAAGGGCGG 540 GGCTTAGAGC TCAACCCAGA CACCTGTAGG TGCCGGAAGCCGCGAAAGTG A 591 195 amino acids amino acid single linear protein NO notprovided adult mouse heart 7 Met Ser Pro Leu Leu Arg Arg Leu Leu Leu ValAla Leu Leu Gln Leu 1 5 10 15 Ala Arg Thr Gln Ala Pro Val Ser Gln PheAsp Gly Pro Ser His Gln 20 25 30 Lys Lys Val Val Pro Trp Ile Asp Val TyrAla Arg Ala Thr Cys Gln 35 40 45 Pro Arg Glu Val Val Val Pro Leu Ser MetGlu Leu Met Gly Asn Val 50 55 60 Val Lys Gln Leu Val Pro Ser Cys Val ThrVal Gln Arg Cys Gly Gly 65 70 75 80 Cys Cys Pro Asp Asp Gly Leu Glu CysVal Pro Thr Gly Gln His Gln 85 90 95 Val Arg Met Gln Val Pro Gly Pro MetGly Gln Ile Leu Met Ile Gln 100 105 110 Tyr Pro Ser Ser Gln Leu Gly GluMet Ser Leu Glu Glu His Ser Gln 115 120 125 Cys Glu Cys Arg Pro Lys LysLys Glu Ser Ala Val Lys Pro Asp Ser 130 135 140 Pro Arg Ile Leu Cys ProPro Cys Thr Gln Arg Arg Gln Arg Pro Asp 145 150 155 160 Pro Arg Thr CysArg Cys Arg Cys Arg Arg Arg Arg Phe Leu His Cys 165 170 175 Gln Gly ArgGly Leu Glu Leu Asn Pro Asp Thr Cys Arg Cys Arg Lys 180 185 190 Pro ArgLys 195 405 base pairs nucleic acid single linear cDNA not provided 8ACCATGAGCC CCCTGCTCCG TCGCCTGCTG CTTGTTGCAC TGCTGCAGCT GGCTCGCACC 60CAGGCCCCTG TGTCCCAGTT TGATGGCCCC AGCCACCAGA AGAAAGTGGT GCCATGGATA 120GACGTTTATG CACGTGCCAC ATGCCAGCCC AGGGAGGTGG TGGTGCCTCT GAGCATGGAA 180CTCATGGGCA ATGTGGTCAA ACAACTAGTG CCCAGCTGTG TGACTGTGCA GCGCTGTGGT 240GGCTGCTGCC CTGACGATGG CCTGGAATGT GTGCCCACTG GGCAACACCA AGTCCGAATG 300CAGATCCTCA TGATCCAGTA CCCGAGCAGT CAGCTGGGGG AGATGTCCCT GGAAGAACAC 360AGCCAATGTG AATGCAGACC AAAAAAAAAA AGGAGAGTGC TGTGA 405 133 amino acidsamino acid single linear protein not provided 9 Met Ser Pro Leu Leu ArgArg Leu Leu Leu Val Ala Leu Leu Gln Leu 1 5 10 15 Ala Arg Thr Gln AlaPro Val Ser Gln Phe Asp Gly Pro Ser His Gln 20 25 30 Lys Lys Val Val ProTrp Ile Asp Val Tyr Ala Arg Ala Thr Cys Gln 35 40 45 Pro Arg Glu Val ValVal Pro Leu Ser Met Glu Leu Met Gly Asn Val 50 55 60 Val Lys Gln Leu ValPro Ser Cys Val Thr Val Gln Arg Cys Gly Gly 65 70 75 80 Cys Cys Pro AspAsp Gly Leu Glu Cys Val Pro Thr Gly Gln His Gln 85 90 95 Val Arg Met GlnIle Leu Met Ile Gln Tyr Pro Ser Ser Gln Leu Gly 100 105 110 Glu Met SerLeu Glu Glu His Ser Gln Cys Glu Cys Arg Pro Lys Lys 115 120 125 Lys ArgArg Val Leu 130 570 base pairs nucleic acid single linear cDNA NO notprovided human fibrosarcoma 10 ACCATGAGCC CTCTGCTCCG CCGCCTGCTGCTCGCCGCAC TCCTGCAGCT GGCCCCCGCC 60 CAGGCCCCTG TCTCCCAGCC TGATGCCCCTGGCCACCAGA GGAAAGTGGT GTCATGGATA 120 GATGTGTATA CTCGCGCTAC CTGCCAGCCCCGGGAGGTGG TGGTGCCCTT GACTGTGGAG 180 CTCATGGGCA CCGTGGCCAA ACAGCTGGTGCCCAGCTGCG TGACTGTGCA GCGCTGTGGT 240 GGCTGCTGCC CTGACGATGG CCTGGAGTGTGTGCCCACTG GGCAGCACCA AGTCCGGATG 300 CAGATCCTCA TGATCCGGTA CCCGAGCAGTCAGCTGGGGG AGATGTCCCT GGAAGAACAC 360 AGCCAGTGTG AATGCAGACC TAAAAAAAAGGACAGTGCTG TGAAGCCAGA CAGCCCCAGG 420 CCCCTCTGCC CACGCTGCAC CCAGCACCACCAGCGCCCTG ACCCCCGGAC CTGCCGCTGC 480 CGCTGCCGAC GCCGCAGCTT CCTCCGTTGCCAAGGGCGGG GCTTAGAGCT CAACCCAGAC 540 ACCTGCAGGT GCCGGAAGCT GCGAAGGTGA570 188 amino acids amino acid single linear protein NO not providedhuman fibrosarcoma 11 Met Ser Pro Leu Leu Arg Arg Leu Leu Leu Ala AlaLeu Leu Gln Leu 1 5 10 15 Ala Pro Ala Gln Ala Pro Val Ser Gln Pro AspAla Pro Gly His Gln 20 25 30 Arg Lys Val Val Ser Trp Ile Asp Val Tyr ThrArg Ala Thr Cys Gln 35 40 45 Pro Arg Glu Val Val Val Pro Leu Thr Val GluLeu Met Gly Thr Val 50 55 60 Ala Lys Gln Leu Val Pro Ser Cys Val Thr ValGln Arg Cys Gly Gly 65 70 75 80 Cys Cys Pro Asp Asp Gly Leu Glu Cys ValPro Thr Gly Gln His Gln 85 90 95 Val Arg Met Gln Ile Leu Met Ile Arg TyrPro Ser Ser Gln Leu Gly 100 105 110 Glu Met Ser Leu Glu Glu His Ser GlnCys Glu Cys Arg Pro Lys Lys 115 120 125 Lys Asp Ser Ala Val Lys Pro AspSer Pro Arg Pro Leu Cys Pro Arg 130 135 140 Cys Thr Gln His His Gln ArgPro Asp Pro Arg Thr Cys Arg Cys Arg 145 150 155 160 Cys Arg Arg Arg SerPhe Leu Arg Cys Gln Gly Arg Gly Leu Glu Leu 165 170 175 Asn Pro Asp ThrCys Arg Cys Arg Lys Leu Arg Arg 180 185 624 base pairs nucleic acidsingle linear cDNA NO not provided mouse 12 ATGAGCCCCC TGCTCCGTCGCCTGCTGCTT GTTGCACTGC TGCAGCTGGC TCGCACCCAG 60 GCCCCTGTGT CCCAGTTTGATGGCCCCAGC CACCAGAAGA AAGTGGTGCC ATGGATAGAC 120 GTTTATGCAC GTGCCACATGCCAGCCCAGG GAGGTGGTGG TGCCTCTGAG CATGGAACTC 180 ATGGGCAATG TGGTCAAACAACTAGTGCCC AGCTGTGTGA CTGTGCAGCG CTGTGGTGGC 240 TGCTGCCCTG ACGATGGCCTGGAATGTGTG CCCACTGGGC AACACCAAGT CCGAATGCAG 300 ATCCTCATGA TCCAGTACCCGAGCAGTCAG CTGGGGGAGA TGTCCCTGGA AGAACACAGC 360 CAATGTGAAT GCAGACCAAAAAAAAAGGAG AGTGCTGTGA AGCCAGACAG GGTTGCCATA 420 CCCCACCACC GTCCCCAGCCCCGCTCTGTT CCGGGCTGGG ACTCTACCCC GGGAGCATCC 480 TCCCCAGCTG ACATCATCCATCCCACTCCA GCCCCAGGAT CCTCTGCCCG CCTTGCACCC 540 AGCGCCGTCA ACGCCCTGACCCCCGGACCT GCCGCTGCCG CTGCAGACGC CGCCGCTTCC 600 TCCATTGCCA AGGGCGGGGCTTAG 624 207 amino acids amino acid linear protein not provided mouse 13Met Ser Pro Leu Leu Arg Arg Leu Leu Leu Val Ala Leu Leu Gln Leu 1 5 1015 Ala Arg Thr Gln Ala Pro Val Ala Gln Phe Asp Gly Pro Ser His Gln 20 2530 Lys Lys Val Val Pro Trp Ile Asp Val Tyr Ala Arg Ala Thr Cys Gln 35 4045 Pro Arg Glu Val Val Val Pro Leu Ser Met Glu Leu Met Gly Asn Val 50 5560 Val Lys Gln Leu Val Pro Ser Cys Val Thr Val Gln Arg Cys Gly Gly 65 7075 80 Cys Cys Pro Asp Asp Gly Leu Glu Cys Val Pro Thr Gly Gln His Gln 8590 95 Val Arg Met Gln Ile Leu Met Ile Gln Tyr Pro Ser Ser Gln Leu Gly100 105 110 Glu Met Ser Leu Glu Glu His Ser Gln Cys Glu Cys Arg Pro LysLys 115 120 125 Lys Glu Ser Ala Val Lys Pro Asp Arg Val Ala Ile Pro HisHis Arg 130 135 140 Pro Gln Pro Arg Ser Val Pro Gly Trp Asp Ser Thr ProGly Ala Ser 145 150 155 160 Ser Pro Ala Asp Ile Ile His Pro Thr Pro AlaPro Gly Ser Ser Ala 165 170 175 Arg Leu Ala Pro Ser Ala Val Asn Ala LeuThr Pro Gly Pro Ala Ala 180 185 190 Ala Ala Ala Asp Ala Ala Ala Ser SerIle Ala Lys Gly Gly Ala 195 200 205 624 base pairs nucleic acid singlelinear cDNA not provided human 14 ATGAGCCCTC TGCTCCGCCG CCTGCTGCTCGCCGCACTCC TGCAGCTGGC CCCCGCCCAG 60 GCCCCTGTCT CCCAGCCTGA TGCCCCTGGCCACCAGAGGA AAGTGGTGTC ATGGATAGAT 120 GTGTATACTC GCGCTACCTG CCAGCCCCGGGAGGTGGTGG TGCCCTTGAC TGTGGAGCTC 180 ATGGGCACCG TGGCCAAACA GCTGGTGCCCAGCTGCGTGA CTGTGCAGCG CTGTGGTGGC 240 TGCTGCCCTG ACGATGGCCT GGAGTGTGTGCCCACTGGGC AGCACCAAGT CCGGATGCAG 300 ATCCTCATGA TCCGGTACCC GAGCAGTCAGCTGGGGGAGA TGTCCCTGGA AGAACACAGC 360 CAGTGTGAAT GCAGACCTAA AAAAAAGGACAGTGCTGTGA AGCCAGACAG GGCTGCCACT 420 CCCCACCACC GTCCCCAGCC CCGTTCTGTTCCGGGCTGGG ACTCTGCCCC CGGAGCACCC 480 TCCCCAGCTG ACATCACCCA TCCCACTCCAGCCCCAGGCC CCTCTGCCCA CGCTGCACCC 540 AGCACCACCA GCGCCCTGAC CCCCGGACCTGCCGCCGCCG CTGCCGACGC CGCAGCTTCC 600 TCCGTTGCCA AGGGCGGGGC TTAG 624 207amino acids amino acid single linear protein not provided human 15 MetSer Pro Leu Leu Arg Arg Leu Leu Leu Ala Ala Leu Leu Gln Leu 1 5 10 15Ala Pro Ala Gln Ala Pro Val Ser Gln Pro Asp Ala Pro Gly His Gln 20 25 30Arg Lys Val Val Ser Trp Ile Asp Val Tyr Thr Arg Ala Thr Cys Gln 35 40 45Pro Arg Glu Val Val Val Pro Leu Thr Val Glu Leu Met Gly Thr Val 50 55 60Ala Lys Gln Leu Val Pro Ser Cys Val Thr Val Gln Arg Cys Gly Gly 65 70 7580 Cys Cys Pro Asp Asp Gly Leu Glu Cys Val Pro Thr Gly Gln His Gln 85 9095 Val Arg Met Gln Ile Leu Met Ile Arg Tyr Pro Ser Ser Gln Leu Gly 100105 110 Glu Met Ser Leu Glu Glu His Ser Gln Cys Glu Cys Arg Pro Lys Lys115 120 125 Lys Asp Ser Ala Val Lys Pro Asp Arg Ala Ala Thr Pro His HisArg 130 135 140 Pro Gln Pro Arg Ser Val Pro Gly Trp Asp Ser Ala Pro GlyAla Pro 145 150 155 160 Ser Pro Ala Asp Ile Thr His Pro Thr Pro Ala ProGly Pro Ser Ala 165 170 175 His Ala Ala Pro Ser Thr Thr Ser Ala Leu ThrPro Gly Pro Ala Ala 180 185 190 Ala Ala Ala Asp Ala Ala Ala Ser Ser ValAla Lys Gly Gly Ala 195 200 205 13 amino acids amino acid single linearpeptide not provided 16 Pro Xaa Cys Val Xaa Xaa Xaa Arg Cys Xaa Gly CysCys 1 5 10 1550 base pairs nucleic acid single linear DNA (genomic) notprovided 17 CTCGAGATCT GTTTGTTGTC TTGGAACAAT ACGGTTTAGA GGTGACTGGCGGGTGACGAG 60 AACATATGCG AGTTCACCTA AGAGAAAAGC TGAATGAGGC AATGCCTCTTCCTGACCATA 120 TCTCTTACTC AGATAACTAT AGAATTTATT GTCCAGTAAA GGGTATATTAAAAAATCATA 180 TTAAAAGTCA TACAGTGAAG TTGTCCAGGG AAATCAAGAC TTAACAGTCTCACTCTGACA 240 ATAATGAACA GGGGGATTCC CTCAAGATAG ACTAGGACAT GACCCCACACTGGCAGGTAG 300 TAGTACCAGA AAAGAACGCA TGGAAAATCT TTACCTTATG CTTGAGGTAGGGACCAGGCT 360 AAAGTGAAGG CCAGACCTAA AATTCTATCT AAAATAAATC CACAATCGAAGAAAATATGT 420 GGTGTACAGG TATAGAATGT CTTTACTGGA TCATTGAAAT AGTAAGATAAATTCAACTTT 480 TTACATTGTT TTCTTTTCCT CCAGTTAGGG CTTGAGACCT TCGTCTCTGGAGAGTGACTG 540 TCAATTGGAG CCCTGCTTTC TGGGTTTCTG GCCAGGGGGG TTGTGGATGCTTAACATGTG 600 CCTTTCACAG GACACTTCCT TACCCCAGCA GTGGCCANGT GTGCATCCCACGACCAGGCC 660 TCCCTCTCAC GGAACATCTG TTGAGACTAG GAGATGCCTG GTGACTGTTGCCTGACCTGT 720 GTCCTGTGTA TTTCTGACAA GAGCCACTCT CAAAGACCCT GGCCAGGAGGAGAGTTAGGT 780 TCCAGTGTAG GTCAGCTCAG ACAGATGGAG GCCACAGAAN CAAACATGGGAAATCACAGA 840 AGTAGGTTTA TTACTCACAG ATCCCTATCC CAACCACCCA GGTGCCCTCTCCTCCAGGGC 900 CAACAGAGGC ATCCTTCAGC AGGAGCGACA ACGGCTAGGG CAGCGGCAAGCCGCCACCAT 960 CCGAGCCAAC CCAGGCCCCG AGATCGTGCC CCGGGGCGCC GGCCCCTGAGGGGCTCACCT 1020 GGATGGGGCC TGCATGCGTT CCCGCTTTGC TTCCTTCCCT GGACGGCCCGCTCCCCCGAA 1080 ACGCGCCGCC AATAAAGTGA TTCGCAGAGC TCGTGTGCGG CTCCCTCCTTAAGGCCCGAC 1140 GCCCCCGGCC CCGGCCTCGC CAAGGGCAGC GCCCCGGCCT CCGGGTAGTGGCGGCCGGCG 1200 ACTGGGGAGC CCAGCCTCCT GGGCGGTGCG TCCCCTTCCC CCTGCCGCGGCGGGAGGCGG 1260 GAGGGGGTGT GTGGAGGAGG CGGGCCCCGC CGACGGCCTC GCCCCCCCACCCCGCCGCCC 1320 CGCCCCCGCC CCACGGGCCC GGTGGGGAGC GCGTGTCTGG GTCACATGAGCCGCCTGCCC 1380 GCCAGCCCGG GCCCAGCCCC CCGCCGCCCC CGCCGTCCCC GCCGCCGCTGCCCGCCGCCA 1440 CCGGCCGCCC GCCCGCCCGG CTCCTCCGGC CGCCTTCGCT GCGCTGCNTGCGCTGCCTGC 1500 ACCCAGGGCT CGGGAGGGGG CCGCGGAGGA GCCGCCCCCC GCGCCCGGCC1550 20 base pairs nucleic acid single linear cDNA not provided 18CACCATGAGC CCTCTGCTCC 20 20 base pairs nucleic acid single linear cDNAnot provided 19 GCCATGTGTC ACCTTCGCAG 20 21 base pairs nucleic acidsingle linear cDNA not provided 20 GGGCATCAGG CTGGGAGACA G 21 18 aminoacids amino acid single linear peptide not provided 21 Cys Pro Val SerGln Phe Asp Gly Pro Ser His Gln Lys Lys Val Val 1 5 10 15 Pro Cys 23amino acids amino acid single linear peptide not provided 22 Ser Gln ProAsp Ala Pro Gly His Gln Arg Lys Val Val Ser Trp Ile 1 5 10 15 Asp ValTyr Thr Arg Ala Thr 20 19 base pairs nucleic acid single linear cDNA notprovided 23 CACAGCCAAT GTGAATGCA 19 31 base pairs nucleic acid singlelinear cDNA not provided 24 GCTCTAAGCC CCGCCCTTGG CAATGGAGGA A 31 28base pairs nucleic acid single linear cDNA not provided 25 ACGTAGATCTTCACTTTCGC GGCTTCCG 28 23 base pairs nucleic acid single linear cDNA notprovided 26 CTCTGTTCCG GGCTGGGACT CTA 23 27 base pairs nucleic acidsingle linear cDNA not provided 27 TCAGGGCGTT GACGGCGCTG GGTGCAA 27 21base pairs nucleic acid single linear cDNA not provided 28 CCTGACGATGGCCTGGAGTG T 21 21 base pairs nucleic acid single linear cDNA notprovided 29 TGTCCCTGGA AGAACACAGC C 21 20 base pairs nucleic acid singlelinear cDNA not provided 30 CGGGAAATCG TGCGTGACAT 20 21 base pairsnucleic acid single linear cDNA not provided 31 GGAGTTGAAG GTAGTTTCGT G21 20 base pairs nucleic acid single linear DNA (genomic) NO notprovided 32 TCGCACCCAG GTACGTGCGT 20 20 base pairs nucleic acid singlelinear DNA (genomic) not provided 33 TTTCCCACAG GCCCCTGTGT 20 20 basepairs nucleic acid single linear DNA (genomic) not provided 34CAGAAGAAAG GTAATAATAG 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 35 CTGCCCACAG TGGTGCCATG 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 36 CCGAATGCAG GTACCAGGGC20 20 base pairs nucleic acid single linear DNA (genomic) not provided37 CTGAGCACAG ATCCTCATGA 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 38 GTGAATGCAG GTGCCAGCCA 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 39 CTCCTCCTAG GGTTGCCATA20 20 base pairs nucleic acid single linear DNA (genomic) not provided40 AGCCAGACAG GTGAGTTTTT 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 41 CTCCTCCTAG GGTTGCCATA 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 42 CCCACTCCAG CCCCAGGATA20 20 base pairs nucleic acid single linear DNA (genomic) not provided43 ACACCTGTAG GTAAGGAGTC 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 44 CACTCCCCAG GTGCCGGAAG 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 45 CCCCGCCCAG GTACGTGCGG20 20 base pairs nucleic acid single linear DNA (genomic) not provided46 TCTCCCACAG GCCCCTGTCT 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 47 CAGAGGAAAG GTAATACTTA 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 48 CTGCTCCCAG TGGTGTCATG20 20 base pairs nucleic acid single linear DNA (genomic) not provided49 CCGGATGCAG GTACTGGGCA 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 50 CTGAGCACAG ATCCTCATGA 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 51 GTGAATGCAG GTGCCAGCCA20 20 base pairs nucleic acid single linear DNA (genomic) not provided52 TACTTTTCAG ACCTAAAAAA 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 53 AGCCAGACAG GTGAGTCTTT 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 54 TCCTCCCTAG GGCTGCCACT20 20 base pairs nucleic acid single linear DNA (genomic) not provided55 CCCACTCCAG CCCCAGGCCC 20 20 base pairs nucleic acid single linear DNA(genomic) not provided 56 ACACCTGCAG GTAGGTTTGG 20 20 base pairs nucleicacid single linear DNA (genomic) not provided 57 CCCTCCTCAG GTGCCGGAAG20

What is claimed is:
 1. An antibody which reacts with a protein whichexhibits a characteristic sequencePro-Xaa-Cys-Val-Xaa-Xaa-Xaa-Arg-Cys-Xaa-Gly-Cys-Cys (SEQ ID NO:16) andwhich protein has the property of promoting proliferation of endothelialcells or mesodermal cells, said protein comprising an amino acidsequence selected from the group consisting of the amino acid sequenceof SEQ ID NO:2, the amino acid sequence of SEQ ID NO:5, the amino acidsequence of SEQ ID NO:7, the amino acid sequence of SEQ ID NO:9, theamino acid sequence of SEQ ID NO:11, the amino acid sequence of SEQ IDNO:13, and the amino acid sequence of SEQ ID NO:15.
 2. An antibodyaccording to claim 1, wherein said antibody is a monoclonal antibody. 3.A method for quantitatively detecting VEGF-B in a test sample,comprising the steps of contacting the sample with an antibody accordingto claim 1, capable of binding VEGF-B in order to detect the amount ofVEGF-B in the sample, and quantitatively detecting the occurrence ofbinding of said antibody.
 4. A diagnostic means according to claim 3,wherein said antibody is a labelled antibody.
 5. A pharmaceuticalcomposition comprising an effective VEGF-B-binding amount of antibodiesaccording to claim 1.